2 | 550,750,900
2 | 275,375,450
3 | 275,375,225
3 | 275,125,75
5 | 275,125,25
5 | 55,25,5
5 | 11,5,5
11 | 11,1,1
LCM:-2×2×3×3×5×5×5×11=49500
What are the solutions to the equation (2x – 5)(3x – 1) = 0? x = or x = 3 x = x = 5 or x = 1
Answer:
x = 5/2 x=1/3
Step-by-step explanation:
(2x – 5)(3x – 1) = 0
Using the zero product property
2x-5 =0 3x-1 =0
2x=5 3x =1
x = 5/2 x=1/3
Answer:
C on edg 2021
Step-by-step explanation:
Which decimal is equivalent to 48 over 100
a. 0.048
b. 0.48
c. 4.08
d. 4.8
Answer:
0.48
Step-by-step explanation:
hope it can work for you mark me as a brain liest
I need Help please answer :((
Answer:
Second option is the correct answer
[tex] {3}^{ - 4} [/tex]
Step-by-step explanation:
[tex] {3}^{ - 8} . {3}^{4} = {3}^{ - 8 + 4} = {3}^{ - 4} [/tex]
Answer:
The answer is D because you multiply the exponents so -8 times 4 is -32
Hope this helps and plz mark branliest!
Step-by-step explanation:
I don’t really understand this…
Steps:
Calculate MU/P
Compare MUx with MUy
Choose highest MU
Continue until you spend all of your money
Answer:
In the real world, a consumer may purchase more then one commodity. Let us assume that a consumer purchases two goods X and Y. How does a consumer spend his fixed money income in purchasing two goods so as to maximize his total utility? The law of equi-marginal utility tells us the way how a consumer maximizes his total utilit
Expand the following using the Binomial Theorem and Pascal’s triangle. Show your work. (x + 2)6 (x − 4)4 (2x + 3)5 (2x − 3y)4 In the expansion of (3a + 4b)8, which of the following are possible variable terms? Explain your reasoning. a2b3; a5b3; ab8; b8; a4b4; a8; ab7; a6b5
Answer:
The answer is below
Step-by-step explanation:
Expansion using pascal triangle:
a) (x + 2)⁶ = x⁶2⁰ + 6(x⁵)(2)¹ + 15(x⁴)(2²) + 20(x³)(2³) + 15(x²)(2⁴) + 6(x)(2⁵) + 1(2⁶)
= x⁶ + 12x⁵ + 60x⁴ + 160x³ + 240x² + 192x + 64
b) (x-4)⁴ = x⁴ + 4(x³)(-4) + 6(x²)(-4)² + 4(x)(-4)³ + 1(x⁰)(-4)⁴
=x⁴-16x³+96x²-256x+256
c) (2x + 3)⁵ = (2x)⁵ + 5(2x)⁴(3) + 10(2x)³(3)² + 10(2x)²(3)³ + 5(2x)(3)⁴ + 1(2x)⁰(3)⁵ =
= 32x⁵ + 240x⁴ + 720x³ + 1080x² + 810x + 243
d) (2x-3y)⁴ = 1(2x)⁴(-3y)⁰ + 4(2x)³(-3y) + 6(2x)²(-3y)² + 4(2x)(-3y)³ + 1(2x)⁰(-3y)⁴
= 16x⁴- 96x³ + 216x² - 216x + 81
Expansion using binomial where [tex]C(n,r)=\frac{n!}{(n-r)!r!}[/tex]
a) (x + 2)⁶ = C(6,0)[x⁶2⁰] + C(6,1)[(x⁵)(2)¹] + C(6,2)[(x⁴)(2²)] + C(6,3)[(x³)(2³)] + C(6,4)[(x²)(2⁴)] + C(6,5)[(x)(2⁵)] + C(6,6)[(2⁶)]
= x⁶2⁰ + 6(x⁵)(2)¹ + 15(x⁴)(2²) + 20(x³)(2³) + 15(x²)(2⁴) + 6(x)(2⁵) + 1(2⁶)
= x⁶ + 12x⁵ + 60x⁴ + 160x³ + 240x² + 192x + 64
b) (x-4)⁴ = C(4,0)[x⁴] + C(4,1)[(x³)(-4)] + C(4,2)[(x²)(-4)²] + C(4,3)[(x)(-4)³] + C(4,4)[(x⁰)(-4)⁴]
= x⁴ + 4(x³)(-4) + 6(x²)(-4)² + 4(x)(-4)³ + 1(x⁰)(-4)⁴
=x⁴-16x³+96x²-256x+256
c) (2x + 3)⁵ = C(5,0)[(2x)⁵] + C(5,1)[(2x)⁴(3)] + C(5,2)[(2x)³(3)²] + C(5,3)[(2x)²(3)³] + C(5,4)[(2x)(3)⁴] + C(5,5)[(2x)⁰(3)⁵]
= (2x)⁵ + 5(2x)⁴(3) + 10(2x)³(3)² + 10(2x)²(3)³ + 5(2x)(3)⁴ + 1(2x)⁰(3)⁵
= 32x⁵ + 240x⁴ + 720x³ + 1080x² + 810x + 243
d) (2x-3y)⁴ = C(4,0){(2x)⁴(-3y)⁰} + C(4,1)[(2x)³(-3y)] + C(4,2)[(2x)²(-3y)²] + C(4,3)[(2x)(-3y)³] + C(4,4)[(2x)⁰(-3y)⁴]
= 1(2x)⁴(-3y)⁰ + 4(2x)³(-3y) + 6(2x)²(-3y)² + 4(2x)(-3y)³ + 1(2x)⁰(-3y)⁴
= 16x⁴- 96x³ + 216x² - 216x + 81
In the expansion of (3a + 4b)⁸, the only possible variable terms are a⁵b³, b⁸, a⁴b⁴, a⁸, ab⁷ because for each of them, the sum of there powers is eight. If the sum of the powers is not 8 then it is not correct.
For a²b³, the sum of the power is 5, for ab⁸ the sum of power is 9 and for a⁶b⁵ the sum of the power is 11 therefore thy are not correct.
As per the question expand the bimonoidal theorem and the pascal triangle. Showing the (x+2)6 (x-4)4 (2x+3)5 (2x-3y)4.
Expansion using pascal triangle:a) (x + 2)⁶ = x⁶2⁰ + 6(x⁵)(2)¹ + 15(x⁴)(2²) + 20(x³)(2³) + 15(x²)(2⁴) + 6(x)(2⁵) + 1(2⁶) = x⁶ + 12x⁵ + 60x⁴ + 160x³ + 240x² + 192x + 64b) (x-4)⁴ = x⁴ + 4(x³)(-4) + 6(x²)(-4)² + 4(x)(-4)³ + 1(x⁰)(-4) =x⁴-16x³+96x²-256x+256c) (2x + 3)⁵ = (2x)⁵ + 5(2x)⁴(3) + 10(2x)³(3)² + 10(2x)²(3)³ + 5(2x)(3)⁴ + 1(2x)⁰(3)⁵ = 32x⁵ + 240x⁴ + 720x³ + 1080x² + 810x + 243d) (2x-3y)⁴ = 1(2x)⁴(-3y)⁰ + 4(2x)³(-3y) + 6(2x)²(-3y)² + 4(2x)(-3y)³ + 1(2x)⁰(-3y)⁴ = 16x⁴- 96x³ + 216x² - 216x + 81.Learn more about the use the binomial theorem.
brainly.com/question/11995132.
When simplified completely, the product of a monomial and a binomial is
a trinomial.
Answer:
the answer is ; Never
Hope this answer correct :)
Answer:
the answer is never
Step-by-step explanation:
Explain how to solve 3^x-4=6 using the change of base formula log base b of y equals log y over log b. include the solution for x in your answer. Round your answer to the nearest thousandth.
Answer:
x = log 10/log 3
Step-by-step explanation:
3^x - 4 = 6
3^x = 10
We take log base 3 of both sides since log_3 3^x is simply x.
log_3 3^x = log_3 10
x = log_3 10
We have an answer for x, but it is a log base 3. We want log base 10.
Now we use the change of base formula.
log_b y = log y/log b
x = log 10/log 3
Factor X squared minus 2X -80
Answer:
(x - 10)(x + 8)
Step-by-step explanation:
x² - 2x - 80
Consider the factors of the constant term (- 80) which sum to give the coefficient of the x- term (- 2)
The factors are - 10 and + 8 , since
- 10 × 8 = - 80 and - 10 + 8 = - 2 , then
x² - 2x - 80 = (x - 10)(x + 8)
1.Origin
2.Y-Axis
3.Run
4.Solution of a Line
5.Ordered Pairs.
6.Quandrant
7.Solution of a Linear equation
8.slope
9.Slope- intercept form
10.Rise
11.Y intercept
12.parallel Lines
13.X intercept
14.x axis
15.Linear equation
16.Perpendicular Lines
17.Point slope Form
18.Coordinate plane
1.Plane with two axes as a frame of reference.
2.The vertical number line in a coordinate plane
3.The horizontal number line in a coordinate plane
4.A pair of numbers that are used to correspond to a point on a graph where the first number is the x-coordinate and the second number is the y-coordinate.
5.where the x and y axis meet. The point (0,0).
6. One of the four regions into which the x and y axis separate the coordinate plane.
7. An equation with two variables that makes up a straight line on a coordinate plane.
8.The vertical change in a line from one point (x1,y1) to a second point (x2,y2).
9. The horizontal change in a line from one point (x1,y1) to a second point (x2,y2).
10.The ratios of a Lines rise over its run.
11.y-y1=m(x-x1)
12.Any of the ordered pairs that make an equation true.
13. Any of the points that are on the line of an equation.
14. The point where a graph crosses the x axis.
15. The point where a graph crosses the y axis
16.A Linear equation in the form y=mx+b, where m is the slope and b is the y-intercept
17. Lines that have the same slope and never intersect.
18.Two Lines that intersect at 90°angle.Slopes of these lines are opposite reciprocals.
Step-by-step explanation:
Origin is 5.
Y Axis is 2
Run is 9
Solution of a Line is 13.
Ordered Pairs is 4.
Quadrant is 6.
Solution of Linear Equation is 12.
Slope is 10.
Slope Intercept Form is 16.
Rise is 8.
Y intercept is 15.
Parallel Lines is 17.
X intercept is 14.
X axis is 3.
Linear Equation is 7.
Perpendicular Lines is 18.
Point Slope Form is 11.
Coordinate plane is 1.
Simplify: (-2)(-3)+(4)(-8)
Simplify: (3)(-6)-18
Answer:
4
Step-by-step explanation:
Answer:
-26, and -36
Step-by-step explanation:
(-2) (-3) + (4) (-8)
6 + -32 = -26
(3) (-6) - 18
-18 + -18 = -36
We have two fractions, \dfrac{1}{6} 6 1 start fraction, 1, divided by, 6, end fraction and \dfrac{3}{8} 8 3 start fraction, 3, divided by, 8, end fraction, and we want to rewrite them so that they have a common denominator (and whole number numerators). What numbers could we use for the denominator? Choose 2 answers: Choose 2 answers: (Choice A) A 121212 (Choice B) B 242424 (Choice C) C 161616 (Choice D) D 4848
Answer:
B) 24
D) 48
Step-by-step explanation:
Given:
Two fractions
[tex]\dfrac{1}6 \\and\\\dfrac{3}8[/tex]
To find:
Number that can be chosen as Common denominator such that numerator is also a whole number ?
Solution:
Common denominator for two fractions [tex]\frac{p}{q}[/tex] and [tex]\frac{r}{s}[/tex] is chosen as LCM or multiple of LCM of (q, s).
OR
Common denominator for two fractions is chosen as the Least Common Multiple or multiple of LCM of denominators of the two fractions.
The denominators of the given fractions are 6 and 8.
Let us factorize and try to find the LCM of 6 and 8.
[tex]6 = \underline2 \times 3\\8 = \underline2 \times 2\times 2[/tex]
Common part of the denominators (as underlined) will be taken only once.
So, [tex]LCM = 2 \times 3 \times 2 \times 2 =24[/tex]
Multiples of LCM, 24 = 48
So, the correct answers are:
B) 24 and
D) 48
PLEASE HELP!!! What is factoring? Why is it useful to try to factor out the GCF first when factoring? Explain the relationship between factoring and multiplying polynomials. Give an example to help explain. Factor x^2-25, 3x^2-12x-15, and x^3+2x^2+3x+6 . What are the key features needed to graph a polynomial function? Explain how to find these key features to sketch a rough graph of a polynomial function. Why would someone want to factor a polynomial? Provide real world examples of different questions we can answer or facts we can determine from factoring a polynomial.
Answer:
What is factoring?Factoring is finding what to multiply to find an expression. It is like splitting expression into a multiplication of simplified expression.
Why is it useful to try to factor out the GCF first when factoring?Greatest common factor or GCF of two numbers is the largest number that divides evenly in both numbers, GCF works the same in polynomials, which divide the expression evenly .
Explain the relationship between factoring and multiplying polynomials. Give an example to help explainFactoring take away the multiplication, to factorize a polynomial it means take apart what is multiplied. the best example is a²+b²+2ab ( multiplied)
factorize :(a+b)(a+b) take apart what is multiplied
Factor x^2-25, 3x^2-12x-15, and x^3+2x^2+3x+6x²-25 =(x+5)(x-5)
3x²-12x-15 = 3(x²-4x-5) GCF=3
3(x-5)(x+1)
x³+2x²+3x+6 (x+2) common factor
(x+2)(x²+3)
What are the key features needed to graph a polynomial function?the key features are the vertex, axis of symmetry, x and y intercept
Explain how to find these key features to sketch a rough graph of a polynomial functionparabola : y=ax²+bx+c
ex: 3x²-12x-15
find vertex (h,k)
h=-b/2a =-(-12)/2(3)=2
k=f(h)=f(2)=3(2)²-12(2)-15
k=12-24-15=-27
vertex=(2,-27)
x intercept is when the graph =0 (y=0)
y intercept when x=0 then y= the constant c and where the graph cross the y axis
axis of symmetry is the x of the vertex: is a line about which a parabola is symmetrical and vertical when the axis of symmetric is vertical.
Why would someone want to factor a polynomial? Provide real world examples of different questions we can answer or facts we can determine from factoring a polynomial.factor a polynomial helps us understand more about equations,factoring helps us rewrite the polynomial into simpler expression.
example from real life:
A homeowner has a back yard and wants to turn it to garden beds so he can plant his vegetables, he wants to fill it with dirt he needs 240 cubic feet to fill it the length is 4 feet than the width , and the height is 4
solve:
length=W+4
height=1/3 w
V=length* width* height
240=(w+4)(w)(4)
351= 4w²+16w
4w²+16w-240=0
take 4 as common factor
4(w²+4w-60)
now factorize:
4(w-6)(w+10)=0
[tex]integrate \: ln(x) [/tex]
Answer:
ln(x) = 1/x... It's a basic rule of Calculus.
If x is 5, then 6x = _____.
Answer:
30
Step-by-step explanation:
if x is 5, then 6x=______.
sub in the value of x for 5
when a variable and coefficient as next to eachother that means to multiply
so 6*5= 30
Answer:
[tex]\large \boxed{\mathrm{30}}[/tex]
Step-by-step explanation:
[tex]x=5[/tex]
[tex]\sf{Substitute \ x \ as \ 5 \ for \ 6x.}[/tex]
[tex]6(5)[/tex]
[tex]6 \times 5 = 30[/tex]
IT IS FOR NOW IM GIVING BRAINLIEST HRRY UP AND 10 POINTS Simplify the expression. What classification describes the resulting polynomial? (8x2 + 3x) − (12x2 − 1) A. linear binomial B. quadratic binomial C. quadratic trinomial D. linear monomial
Answer:
The equation would be a quadratic trinomial
Step-by-step explanation:
Step 1: Expand the equation to remove the brackets
0 = 8x² + 3x - 12x² + 1
Step 2: Collect like terms
0 = -4x² + 3x + 1
Step 3: Count number of terms
0 = -4x² + 3x + 1
1 2 3
Therefore there are 3 terms and this is a quadratic equation making the answer B, a quadratic trinomial
The citizens of a certain community were asked to choose their favorite pet. The pie chart below shows the distribution of the citizens' answers. If there are 140,000 citizens in the community, how many chose Fish or Cats?
Incomplete Question:
The content of the pie chart is as follows:
Hamsters = 9% ; Snakes = 10% ; Cats = 23%
Birds = 21% ; Dogs = 26% ; Fish = 11%
Answer:
The number of citizens who chose cat or fish is 47,600
Step-by-step explanation:
Given
Number of citizens = 140,000
Required
Determine the number of those that chose fish or cats
First, we need to calculate the percentage of those whose pets are either cats or fish
[tex]Percentage = Cat + Fish[/tex]
Substitute 23% for cat and 11% for fish
[tex]Percentage = 23\% + 11\%[/tex]
[tex]Percentage = 34\%[/tex]
Next, is to multiply the calculated percentage by the number of citizens
[tex]Cat\ or\ Fish = Percentage * Number\ of\ Citizens[/tex]
[tex]Cat\ or\ Fish = 34\% * 140000[/tex]
[tex]Cat\ or\ fish = 47600[/tex]
Hence, the number of citizens who chose cat or fish is 47,600
the number of citizens who chose cat or fish is 47,600
The calculation is as follows;= Number of citizens × total percentage
[tex]= 140,000 \times (23\% + 11\%)\\\\= 140,000 \times 34\%[/tex]
= 47,600
Learn more: https://brainly.com/question/17429689?referrer=searchResults
answer
answer
answer
answer
Please..
Answer:
It's true. We can write integers in fraction by giving it a denominator of 1.
Answer:
true
Step-by-step explanation:
Point A is located at (0, 4), and point C is located at (−3, 5). Find the x value for the point B that is located one-fourth the distance from point A to point C.
Answer:
x = (-2 , 4.5)
Step-by-step explanation
Hope it helps! later!
One fifth of a number is subtracted from one fourth of the number,the result is 8 more than 10.Find the number
Answer:
4
Step-by-step explanation:
Let the number be x.
According to the question,
[tex]\dashrightarrow \sf { \dfrac{1}{4}x - \dfrac{1}{5}x= 8 + 10 } \\[/tex]
[tex]\dashrightarrow \sf { \dfrac{5x + 4x}{2}= 18 } \\[/tex]
[tex]\dashrightarrow \sf { \dfrac{9x}{2}= 18 } \\[/tex]
[tex]\dashrightarrow \sf { 9x = 18 \times 2 } \\[/tex]
[tex]\dashrightarrow \sf { 9x = 36 } \\[/tex]
[tex]\dashrightarrow \sf { x =\cancel{ \dfrac{36}{9} }} \\[/tex]
[tex]\dashrightarrow \underline{\boxed{\pmb { \frak {x = 4 }}}} \\[/tex]
The number is 4.
You need to prepare 30mL solution of a 1:8 syrup solution. You have on hand 50% syrup solution and a 1:20 soda solution. How many mL of each solution do you need to create the final solution?
Answer:
5 ml of 50% syrup solution will be used to create the final solution
Step by step Explanation:
Let the amount of 50% solution that was used = b
Which means ( 30 - b ) is the amount of 1/200 solution used then we can derive an equation as follows,
set up will then be,
0.5b +0.05(30 -b) = 1/8 (30)
We can simplifiy this as
0.5b+ 1.5 -0.05b = 3.75
Then make b the subject of the formula we have
0.45b = 2.25
b= 2.25/0.45
b = 5 ml
Therefore, 5ml of 50% syrup solution will be used to create the final solution
The area of a trapezium is 105cm² and its height is 7 cm. If one of the parallel sides is longer than the other by 6cm, find the lengths of two parallel sides.
Answer:
Step-by-step explanation:
Given the sequence 4, 8, 16, 32, 64, ..., find the explicit formula. A. an=10(2n−1) B. an=5(2n−1) C. an=4(2n−1) D. an=20(2n−1)
Answer:
. an=4(2n−1)
Step-by-step explanation:
Simplify to create an equivalent expression. −3(2+4k)+7(2k−1)
Answer:
[tex]\huge\boxed{2k-13}[/tex]
Step-by-step explanation:
[tex]\sf -3(2+4k)+7(2k-1)\\Expanding \ brackets\\-6-12k+14k-7\\Combining \ like \ terms\\-12k+14k-6-7\\2k -13[/tex]
-14 = x - 12 pls answer this if I can and check answer
Answer:
x = -2
Step-by-step explanation:
-14 = x - 12
-14 + 12 = x
-2 = x
check:
-14 = -2 - 12
classify what type of number is 8/2
Answer:
unsimplified improper fraction
Step-by-step explanation:
8/2 could be simplified into 4 and its an improper fraction bc proper fraction form is 4/1 or just 4
2. At a local restaurant, 55% of people order an appetizer to start while 25%
order a salad to start. Also, 18% choose both an appetizer and a salad to start.
What percentage of people order a salad or an appetizer to start?
Answer:
Probability of people order a salad or an appetizer P(A∪B) = 62%
Step-by-step explanation:
Given:
Probability of appetizer P(A) = 55%
Probability of salad P(B) = 25%
Probability of choose both P(A∩B) = 18%
Find:
Probability of people order a salad or an appetizer P(A∪B)
Computation:
P(A∪B) = P(A) + P(B) - P(A∩B)
P(A∪B) = 55% + 25% - 18%
P(A∪B) = 62%
Probability of people order a salad or an appetizer P(A∪B) = 62%
2/4.7+2/7.10+2/10.13+2/13.16+.....+2/49.52
tính giá trị biểu thức
It looks like you're trying to evaluate the sum,
[tex]\displaystyle \frac2{4\times7} + \frac2{7\times10} + \frac2{10\times13}+\cdots+\frac2{49\times52}[/tex]
which can be written as
[tex]\displaystyle \sum_{n=1}^{16} \frac2{(3n+1)(3n+4)}[/tex]
Split up the summand into partial fractions:
[tex]\displaystyle \frac2{(3n+1)(3n+4)} = \frac a{3n+1} + \frac b{3n+4} \\\\ \implies 2 = a(3n+4)+b(3n+1) \\\\ \implies 2 = (3a+3b)n+4a+b[/tex]
so that
3a + 3b = 0, or a = -b
4a + b = 2
Solve for a and b :
4a + (-a) = 3a = 2 ==> a = 2/3 ==> b = -2/3
So the sum is
[tex]\displaystyle \frac23 \sum_{n=1}^{16} \left(\frac1{3n+1} - \frac1{3n+4}\right)[/tex]
Write out the first terms and observe that several terms cancel with each other:
2/3 (1/4 - 1/7)
+ 2/3 (1/7 - 1/10)
+ 2/3 (1/10 - 1/13)
+ …
+ 2/3 (1/43 - 1/46)
+ 2/3 (1/46 - 1/49)
+ 2/3 (1/49 - 1/52)
So the sum collapses and simplifies to
[tex]\displaystyle \sum_{n=1}^{16} \frac2{(3n+1)(3n+4)} = \frac23 \left(\frac14 - \frac1{52}\right) = \boxed{\frac2{13}}[/tex]
what is 1680 mm in feet
5.51181102 feet (5 feet 6 9⁄64 inches)
13. A map has a scale of 2 cm to 3 km.
(iii) If the actual area of a lake is 81 km?, calculate
its area on the map.
Scale = 1cm:3km
Therefore area of lake = 81Km
1:3 = x:81
= 27:81
Therefore the area on map is 27cm
Must click thanks and mark brainliest
Answer:
121.5 is answer.
Step-by-step explanation:
81 / 2 = 40.540.5 *3 = 121.50. A submarine was at sea level and
then dove 752 ft. It then rose at a rate
of 12 ft. per minute. What was the
depth of the submarine after 8
minutes?
Also idk the equation so if u could help me out with that id be grateful
One equation you can use is y = -12x+752 and you plug in x = 8 to find y.
=================================================
Explanation:
x = number of minutes
y = depth of the submarine
Being at sea level means the depth is y = 0. Diving 752 ft below sea level means the depth is y = 752. It's tempting to make this negative since we're below sea level, but depth values are always positive. They are simply distances you are from the surface of the water. Negative distances are never possible. So this concept might be a bit tricky to get used to.
Possibly equally confusing is the fact that the "12 ft per minute" means the slope is -12. This is because the depth is getting smaller as the submarine gets closer to the surface (aka the sub is rising).
The equation is y = -12x+752. The equation is in the form y = mx+b with m = -12 as the slope and b = 752 as the y intercept. Note how the y intercept is the starting depth value.
From here, we plug in x = 8 to find where the sub is
y = -12x+752
y = -12*8+752
y = -96+752
y = 656
The submarine's depth after eight minutes is 656 feet
----------------------
An alternative equation to use is
y = 12x-752
which is very similar to the other one used earlier. All I did was flip the sign of each term. Now y represents the height of the sub. Negative y values indicate we're below the surface of the water. The slope being positive means the submarine is going upward. The negative y intercept indicates we're starting 752 feet below sea level. Plugging in x = 8 will lead to y = -656, which you'll need to make positive (since all depth values are positive).
As you can probably guess, the change from y = -12x+752 and y = 12x-752 is simply multiplying the right hand side by -1, which explains why the signs flip (and explains how the y value sign flips as well)