plz help, will mark brainliest!

Answer:

f(4) = 3

Step-by-step explanation:

f(x) = -[tex]x^{2}[/tex] + 8x - 13

To find f(4), substitute 4 for all instances of x:

f(4) = -(4[tex])^{2}[/tex] + 8(4) - 13

Simplify the exponent:

f(4) = -16 + 8(4) - 13

Multiply:

f(4) = -16 + 32 - 13

Combine terms:

f(4) = 3

Answer:

3

Step-by-step explanation:

You plug in 4.

f(4)= -(4)^2+8(4)-13

f(4)= -16+32-13

f(4)= 16-13

f(4)=3

Answer: Khan Academy 2020! The answer is 40!

Step-by-step explanation:

Answer:

40

Step-by-step explanation:

Answer: -2

Step-by-step explanation:

Answer:

-2

Step-by-step explanation:

the above photos is the solution

Step-by-step explanation:

The shoes are bought for $60 and were 40% off which means $60 is 60% of the original price

if 60% = $60 the 100% = $100 (the price of the shoe before discount).

Answer:

Yes, that is correct.

Step-by-step explanation:

W = x

L = ?

A = x^2 + 12x

(x^2 + 12x)/x = x + 12

L = x + 12

Subbing in 10 for each X, we get:

Perimeter: 64

2(10) + 2(10 + 12) = 20 + 44 = 64

Area: 220

10 * 22 = 220

Part A looks perfect. You've shown that x^2+12x factors into x(x+12) indicating that x is the width and x+12 is the length. Convention usually has the length be longer than the width, but to be honest, the order doesn't really matter (since we can multiply in any order we want).

----------------

Part B is a bit hazy. You show that 10 * 22 = 220 is the area, so you imply that the rectangle has width 10 and length 22. However, you don't directly mention the dimensions of the rectangle.

You can pick either x^2+12x or x(x+12). I prefer x(x+12) as its easier in my opinion. You don't need to do both.

All you really need to do is say that if x is the width and x = 10, then the width is 10. Furthermore, if x+12 is the length then x+12 = 10+12 = 22 is the length.

Answer:

[tex]\boxed{392in^2}[/tex]

Step-by-step explanation:

Hey there!

Well to find SA we need to find the area of the rectangles.

So lets do the top rectangle,

6*6 = 36

Now lets do the the left rectangle,

10*6 = 60

Now lets do the far right one,

6*4 = 24

Now lets do the second highest rectangle,

4*6 = 24

Now lets do the rectangle facing the right side,

6*6 = 36

Now we can do the bottom rectangle,

6*10 = 60

Now lets do the 2 facing front and back,

6*10 = 60

4*4 = 16

60+16 = 76

76*2 = 152

Now we can add everything,

152 + 60 + 36 + 24 + 24 + 60 + 36

= 392 in^2

Hope this helps :)

Answer:

1. b.  2. a.  3. a.

Step-by-step explanation:

1. (f + g)x = f(x) + g(x)

= x^2 + 2x + 4

(f + g)(-1) =  (f + g)(x)  where x = 1 so it is

(-1)^2 + 2(-1) + 4

=  1 - 2 + 4

= 3.

2.  We find (f o g)(x) by replacing the x in f(x) by g(x):

= √(x + 1) and

(f o g)(3) =  √(3 + 1)

= √4

= 2.

3. (f/g) c  = f(x) / g(x)

= (x - 3)/(x + 1)

The domain is the values of x which give real values of (f/g).

x cannot be - 1 because the denominator x + 1 = -1+1 = 0 and dividing by zero is undefined. So x can be all real values of x except x = -1.

The domain is (-∞, -1) U (-1, ∞)

Answer:

It would take 6 days for Sam and Betty to paint the same house together.

Step-by-step explanation:

Let x represent the time it takes ( in days ) to complete painting the house working together. Our approach here is to add the rates of the two people, equal to the total rate, or 1 / 7.

Sam's rate = 1 / 7 ( 7 days to paint 1 house ),

Betty's rate = 1 / 42 ( 42 days to paint 1 house )

1 / 7 + 1 / 42 = 1 / x - now let us solve for x, our solution

1 / 7 + 1 / 42 = 1 / x ( multiply either side by 42x )

7x = 42,

x = 42 / 7 = 6 days

Answer:

Step-by-step explanation:

find LCM of the denominators= 77

so 66/77 - 63/77

3/77

hope this help you pls mark me as brainliest

working for division is on this question is

6/7 divide 9/11

so 6/7 *11/9

66/63 and then you can find its standard form and it cannot be do not

Answer:

7

Step-by-step explanation:

Answer: just read

Step-by-step explanation:

So first you plot the points, then calculate how many units it takes from the point that is Sean’s house to his School. Show your work on that by drawing out your skip counting. Then you plot the rest of the points and fpro this calculation: the distance from Sean’s house to his school+ from his school to the grocery store. Then you calculate the distance (in units! ! ! Which means one box is one unit) : distance from Sean’s house to the school+ from school to the commmunity center. Then two calculations you made above you compare. So whichever one is greater is your answer for part b.

Answer: Speed  of first bird =41 mph

Speed of second bird = 26 mph

Step-by-step explanation:

Let x be the speed of the second bird, then the speed of first bird will be x+15.

After 6 hours ,

Distance covered by first bird= (x+15)(6)      [Distance = speed × time]

= 6x+90

Distance covered by second bird= (x)(6) = 6x

After 6 hours the two birds are 402 miles apart.

[tex]\Rightarrow\ 6x+90+6x=402\\\\\Rightarrrow\ 12x=402-90\\\\\Rightarrow\ 12x=312\\\\\Rightarrow\ x=\dfrac{312}{12}\\\\\Rightarrow\ x=\dfrac{312}{12}=26[/tex]

Speed of second bird = 26 mph, Speed  of first bird = 26+15 = 41 mph.

Answer:

80°

Step-by-step explanation:

Answer: A, B and, C are incorrect, what is D?

Step-by-step explanation:

3.35 (3 sig.fig)

Triangle ABC

AC = BC, AB = 3, CD perpendicular to AB, CD =3

AC (Hypotenuse)

AC = BC shows that Triangle ABC is an isosceles triangle.

As CD is perpendicular to AB, and, both sides

(AC & BC) have equal angles and length, making the line CD cut right across the triangle.

(Point D is in the middle of Line AB)

Resulting in 2 EQUAL triangles in Triangle ABC.

To find one of the 2 triangles:

1. Take Line AB and divide it in half as both sides are equal.

Line AD = 3 / 2

= 1.5

2. Use the Pythagoras Theorem to find Line AC (Hypotenuse). [c^2 = a^2 + b^2]

a : Line AD = 1.5

b : Line CD = 3

c^2 = 1.5^2 + 3^2

c^2 = 2.25 + 9

c^2 = 11.25

c = (Square Root) 11.25

c = 3.35 (3 significant figure)

Therefore, the answer is:

3.35

Answer:

I believe it might be 2over 6

Step-by-step explanation:

my guess but it might be wrong or right i dont know

Answer:

[tex]x=\frac{2}{5}y-2[/tex]

Step-by-step explanation:

[tex]-5x+2y=10\\-5x+2y-2y=10-2y\\-5x=2y-10\\\frac{-5x}{-5}=\frac{2y-10}{5}\\ x=\frac{2}{5}y-2[/tex]

Answer:

To have maximum profit, the price must be increased by 5,

Step-by-step explanation:

Given that the price increase function is:

f(x) = -2x² + 20x + 150,

For maximum profit, then f(x) = 0.

Putting f(x) = 0, we have

-2x² + 20x + 150 = 0

Or

x² - 10x - 75 = 0

(x + 5)(x - 15) = 0

x = -5

Or

x = 15

Again, differentiating f(x) and equating to zero, we have

-4x + 20 = 0

4x = 20

x = 20/4

= 5

To have maximum profit, the price must be increased by 5,

Answer:

[tex] 0.7287[/tex]

Step-by-step explanation:

Let $534.9=a$

Thus, given:

$\log a=2.7287$

Hence:

$\log \Big( \frac{a}{100}\Big)=\log a- \log 100$

$\implies \log \Big( \frac{a}{100}\Big)=2.7287-2=0.7287$

Answer:

a)

[tex](4.3 \times {10}^{5} )(1.6 \times {10}^{4} ) = 6.88 \times {10}^{9} [/tex]

b)

[tex](2.25 \times {10}^{3} )(5.8 \times {10}^{6} ) = 13.05 \times {10}^{9} = 1.305 \times {10}^{10} [/tex]

I hope I helped you ^_^

Answer:

<9 =144

Step-by-step explanation:

<1 + <4 + < 6 + <9 = 360

36+ 49+ 131 + <9 = 360

216 +  < 9 = 360

< 9 = 360-216

<9 =144

Answer:

A. 144

Step-by-step explanation:

Since m<6 + m<4 = 131 + 49 = 180, then FE is a line.

Angles 1 and 9 are a linear pair, so they are supplementary.

m<9 + m<1 = 180

m<9 + 36 = 180

m<9 = 144

Answer:

your anwser is 4 x + 2 y − 3 z − 3

Step-by-step explanation:

Simplify:4 x + 2 y − 3 z − 3

Answer:

4x + 2y - 3z -3.

Step-by-step explanation:

2x+5y+z-6)+(6x-4y-z+7)+(-4x+y-3z-4)

Removing the parentheses:

= 2x + 5y + z - 6 + 6x - 4y - z + 7 - 4x + y - 3z - 4

Bringing like terms together:

= 2x + 6x - 4x + 5y - 4y + y + z - z - 3z - 6 + 7 - 4

Simplifying like terms we have:

4x + 2y - 3z -3.

Answer:

Enlargement

Step-by-step explanation

It is enlargement, because it went up by three. Instead of reducing.

We cannot tell the result because the actual size of blocks used for modelling the Empire State Building is not known.

For a particular scaled construct, it is already specified that all the measurements' some constant scaled version will be taken. For example, let the scale be K feet to s inches.

Then it means

[tex]\rm 1\: ft : \dfrac{s}{k}\: in.[/tex]

All feet measurements will then be multiplied by s/k to get the corresponding lengths in the constructed scaled structure.

For case a) or b), we used the scale factors as:

1 block : x feet, where x was either 2 or 5 feet.

But we are not specified what size is of the block which is used to model the building.

It may be that block is greater than x feet, or may be smaller. This will decide whether there is enlargement or reduction of the actual building, respectively.

Thus, we cannot tell the result because the actual size of blocks used for modelling the Empire State Building is not known.

Learn more about scale factors here :

https://brainly.com/question/8765466

Answer:

Step-by-step explanation: I hope it helps :)

[tex]-1.5(4-r)=-12\\\\\mathrm{Multiply\:both\:sides\:by\:}10\\\\-1.5\left(4-r\right)\cdot \:10=-12\cdot \:10\\\\= -15\left(4-r\right)=-120\\\\\mathrm{Divide\:both\:sides\:by\:}-15\\\\\frac{-15\left(4-r\right)}{-15}=\frac{-120}{-15}\\\\4-r=8\\\\\mathrm{Subtract\:}4\mathrm{\:from\:both\:sides}\\\\4-r-4=8-4\\\\-r=4\\\\\mathrm{Divide\:both\:sides\:by\:}-1\\\\\frac{-r}{-1}=\frac{4}{-1}\\\\r=-4[/tex]

Answer:

r = -4

Step-by-step explanation:

-1.5(4-r)=-12

Divide each side by -1.5

-1.5/-1.5(4-r)=-12/-1.5

(4-r)=8

Subtract 4 from each side

4-r-4 = 8-4

-r = 4

Divide each side by -1

r = -4

Answer:

Tan D = 7 / 4

Sin D = 7 / 8.1

Cos D = 4 / 8.1

IG = 4.95 Cm

Step-by-step explanation:

In question number 3

Tan D = Perpendicular / Base

Tan D = 7 / 4

Sin D = Perpendicular / hypotenuse

Sin D = 7 / 8.1

Cos D = Base / hypotenuse

Cos D = 4 / 8.1

In question number 4

Tan 68° = IG / GH

2.475 = IG / 2

IG = 4.95 Cm