Joan weighs 10 pounds less than her older sister. The average of the two sisters’ weights is 85 pounds. How much does Joan’s older sister weigh?

Answer:

The expression in factored form is (3x - 7)(3x + 7)

Step-by-step explanation:

Here in this question, we are interested in using the difference of two squares to factor the given expression.

Mathematically, supposed we have two squares a^2 and b^2, and we are told to factorize a^2-b^2.

By using the difference of two squares;

a^2-b^2 can thus be written as;

(a-b)(a + b)

Now, we can apply same approach to the problem at hand.

9x^2 - 49

kindly note that 9x^2 can be written as ((3x)^2 and 49 can be written as 7^2

So applying what we have said earlier about difference of two squares;

9x^2 - 49 will be ;

(3x-7)(3x + 7)

Answer:

The answer is (3x - 7) (3x +7)

Step-by-step explanation:

Answer:

x = -1.5

Step-by-step explanation:

16x - 5 = 18x -2

Subtract 16x from each side

16x-16x - 5 = 18x-16x -2

-5 = 2x-2

Add 2 to each side

-5+2 = 2x-2+2

-3 = 2x

Divide by 2

-3/2 = 2x/2

-3/2 =x

Answer:

-3/2

Step-by-step explanation:

To solve this problem, start by moving all of your x's on to one side, and all of your constants on to the other as such:

16x-5=18x-2

     +2       +2

16x-3=18x

-16x    -16x

-3=2x

-3/2 = x

P.S. please give me brainliest. Thank you! :)

Answer:

true

Step-by-step explanation:

A matrix can only be added/subtracted with another matrix if the two matrices have the same dimensions

Answer:  Choice A)  -3

Work Shown:

[tex]\log_{2}(x+7) = 2\\\\x+7 = 2^2\\\\x+7 = 4\\\\x = 4-7\\\\x = -3\\\\[/tex]

Which leads us to choice A. In the second step, I used the rule that [tex]\log_b(y) = x[/tex] is equivalent to [tex]y = b^x[/tex]. For each equation, the b is the base. Note how logs undo exponents and vice versa.

Answer:

-3

Step-by-step explanation:

log2(x+7) = 2​

Raise each side by base 2

2^log2(x+7) = 2^2​

x+7 = 4

Subtract 7 from each side

x+7-7 = 4-7

x=-3

Answer:

Two solutions: -0.12 and 1.75.

Step-by-step explanation:

The quadratic formula is:

[tex]\begin{array}{*{20}c} {\frac{{ - b \pm \sqrt {b^2 - 4ac} }}{{2a}}} \end{array}[/tex]. Assuming that the x² term is a, the x term is b, and the constant is c, we can plug the values into the equation.

[tex]\begin{array}{*{20}c}{\frac{{ - 8 \pm \sqrt {8^2 - 4\cdot-4.9\cdot1} }}{{2\cdot-4.9}}} \end{array}[/tex]

[tex]\begin{array}{*{20}c}{\frac{{ - 8 \pm \sqrt {64 + 19.6} }}{{-9.8}}} \end{array}[/tex]

[tex]\begin{array}{*{20}c}{\frac{{ - 8 \pm \sqrt {83.6} }}{{-9.8}}} \end{array}[/tex]

[tex]\begin{array}{*{20}c}{\frac{{ - 8 \pm \sqrt {9.14} }}{{-9.8}}} \end{array}[/tex]

[tex]\frac{-8 + 9.14}{-9.8} = -0.12[/tex]

[tex]\frac{-8-9.14}{-9.8} =1.75[/tex]

Hope this helped!

Answer:

4 times the sum of 21 and a number

Step-by-step explanation:

4(21+ n)

The four is being multiplied by the sum of 21 and n

Answer:

[tex]\huge\boxed{x = -\frac{5}{6}}[/tex]

Step-by-step explanation:

[tex]f(x) = -12x+7[/tex]

Given that f(x) = 17

[tex]17 = -12x+7[/tex]

Subtracting 7 to both sides

[tex]17-7 = -12x[/tex]

10 =  -12 x

Dividing both sides by 12

[tex]x = - \frac{10}{12}[/tex]

[tex]x = -\frac{5}{6}[/tex]

Answer:

-5/6 =x

Step-by-step explanation:

f(x) = -12x+7

We want to find x when f(x) = 17

17 = -12x+7

Subtract 7 from each side

17-7 = -12x +7-7

10 = -12x

Divide each side by 12

10/-12 = -12x/-12

-5/6 =x

Answer:

8

Step-by-step explanation:

|6x| - |- 2y|

Let x = -3 and y = 5

|6*-3| - |- 2*5|

|-18| - |-10|

Taking the absolute values

18 - 10

8

Answer:

45.94%

Step-by-step explanation:

Probability-Above 45.94%

Z =0.1  

x= 61

µ 60

σ 9.8

Answer:

6x - 4

Step-by-step explanation:

4 less than 6 times x

6x - 4

If my answer is incorrect, pls correct me!

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-Chetan K

Answer:

D

Step-by-step explanation:

(f+g)(x) = f(x) + g(x)

=3x + 9 + 5x²

=5x² + 3x + 9

Answer:

17) 120°

18) 85°

Step-by-step explanation:

→ Find the sum of angles in each shape

Quadrilateral = 360°

Triangle = 180°

→ Add the angles together and subtract it from the sum

360 - ( 80 + 80 + 80 ) = 120° for number 17

180 - ( 35 + 60 ) = 85° for number 18

Answer:

JKM is acute and MKL is obtuse

Step-by-step explanation:

because an acute triangle's interior angles are always 180° and an obtuse triangle's sum is greater than 90°

Answer:

0

Step-by-step explanation:

the x after the 10 is literally just 1

so 10 x 1  =10

-10 + 10 = 0

Answer:

a = 38

Step-by-step explanation:

The two angles add to 90 degrees

a+52 = 90

a = 90-52

a = 38

Answer:

Below

Step-by-step explanation:

The little box on the angle indicates that it is 90 degrees

All you need to do now to find angle a is to subtract 52 from 90...

90 - 52 = 38 degrees

Hope this helped!

Answer:

[tex]2\sqrt{3}[/tex]

Step-by-step explanation:

I'm assuming the angles are in degrees.

[tex]2x \tan(60\º)=10+\csc(30\º)[/tex]

[tex]$2x\cdot \sqrt{3}=10+\frac{1}{\sin(30\º)} $[/tex]

[tex]$2x\cdot \sqrt{3}=10+\frac{1}{\frac{1}{2} } $[/tex]

[tex]$2x\cdot \sqrt{3}=10+2} $[/tex]

[tex]$x=\frac{12}{2\sqrt{3}} $[/tex]

[tex]$x=\frac{6}{\sqrt{3}} =\frac{6\sqrt{3}} {3} }=2\sqrt{3} $[/tex]

Answer:

The error she made was that she was adding x and 2.75. She should subtract 2.75 from x.

Another mistake that she made was that she sold each for $7 assuming that she would make a profit of 78, but she should see each necklace for $12.5 so that she could make a profit of $78.

Step-by-step explanation:

The error she made was that she was adding x and 2.75.

She should write the equation as 8 (x - 2.75) = 78; as she spends $2.75 to make a necklace.

By using the correct equation: 8 (x - 2.75) = 78

=> 8x - 22 = 78

=> 8x = 78 + 22

=> 8x = 100

=> x = 100/8

=> x = 12.5

Another mistake that she made was that she sold each for $7 assuming that she would make a profit of 78, but she should see each necklace for $12.5 so that she could make a profit of $78.

Hope this helps you.

Answer:

C

Step-by-step explanation: Nice

Answer: 19 yards

Step-by-step explanation: 9.5x2=19

Answer:

-7/2

Step-by-step explanation:

cuz thats right

Answer:

[tex]2\sqrt{3}+3[/tex]

Step-by-step explanation:

[tex]$\frac{3}{2 \sqrt 3 - 3}$[/tex]

Rationalize the fraction.

[tex]$\frac{3}{2 \sqrt 3 - 3}\cdot \frac{2 \sqrt 3 + 3}{2 \sqrt 3 + 3} =\frac{6\sqrt{3}+9 }{12-9} =\frac{6\sqrt{3}+9 }{3} =2\sqrt{3}+3 $[/tex]

Note that I used the positive signal because we would have a difference of squares.

Answer:

The four legged stool is the one that rocks slightly from side to side. The three legged stool does not.

Step-by-step explanation:

The four legged stool is the one that rocks slightly because the three legs determine a plane, and the three legs are stuck on that single plane.

Answer: First degree equation

Step-by-step explanation:

For each hour from 5pm , the temperature decreases 5F. So, let the variation of time t , the constant -5, and the final temperature, T:

T=5t-5 .: for 5pm , variation is 0,so T in F is -5.

Answer:

probably First degree equation

Step-by-step explanation:

Answer:

0.000000047

Step-by-step explanation:

The equation is written as 3x + 7 = x - 15. And the solution of the equation will be negative 11.

The allocation of weights to the important variables that produce the calculation's optimum is referred to as a direct consequence.

Multiple times the amount of a number expanded by 7 is equivalent to a similar number diminished by 15.

Let the number be 'x'.

The three times the number plus 7. Then the expression is given as,

⇒ 3x + 7

The number 'x' is decreased by 15. Then the expression is given as,

⇒ x - 15

Both expressions are equal to each other. Then we have

3x + 7 = x - 15

3x - x = - 15 - 7

2x = - 22

x = - 11

The equation is written as 3x + 7 = x - 15. And the solution of the equation will be negative 11.

More about the solution of the equation link is given below.

https://brainly.com/question/545403

#SPJ2

Answer:

A) The percentage is given by (The new value)/(The old value)*100 = 120%

B) The increase in value is $90000

C) The increase as a percentage is (90000/450000)*100=20%

a. The new value is 120% of the old value.

b. The increase in value over the three-year period is $90 000.

c. The increase in value over the three-year period is 20% of the original value.

The percentage is defined as a ratio expressed as a fraction of 100.

a. To find the new value as a percentage of the old value, we can divide the new value by the old value and multiply by 100 to get a percentage:

New value as a percentage of old value = (New value / Old value) x 100%

= ($540 000 / $450 000) x 100%

= 120%

Therefore, the new value is 120% of the old value.

b. To find the increase in value over the three-year period, we can subtract the old value from the new value:

Increase in value = New value - Old value

= $540 000 - $450 000

= $90 000

Therefore, the increase in value over the three-year period is $90 000.

c. To find the increase in value as a percentage of the original value, we can divide the increase in value by the old value and multiply by 100 to get a percentage:

Increase in value as a percentage of original value = (Increase in value / Old value) x 100%

= ($90 000 / $450 000) x 100%

= 20%

Therefore, the increase in value over the three-year period is 20% of the original value.

Learn more about the percentages here:

brainly.com/question/24159063

#SPJ2

Answer:

1) The ship is closer

2) 675.73 m

Step-by-step explanation:

1) The given parameters are;

The initial angle between the ship's course and the lighthouse = 32°

The final angle between the ship's course and the lighthouse = 72°

The distance traveled by the sip between he two positions = 1500 m

Therefore we have a triangle formed between the distance covered by the ship and the two distances of the ship from the lighthouse, a and b

Where;

a = The initial distance fro the lighthouse

b = The final distance fro the lighthouse

The angles of the triangle are

32°, (180 - 72) = 108° and 180 - 32 - 108 = 40°

By sine rule we have;

1500/(sin(40)) = a/(sin(108)) = b/(sin(32)) =

Therefore, a = sin(108°) × 1500/(sin(40°)) = 2219.37 m

b = (sin(32°)) × 1500/(sin(40°)) = 1236.61 m

Therefore, a  > b

The initial distance fro the lighthouse > The final distance fro the lighthouse, which shows that the ship is closer

2) By cosine rule we have

a² = b² + c² - 2× b×c×cos(A)

Where the given measurements by Kendra are;

410 m and 805 m with an included (in between) angle of 57°, we have;

Let b = 410 m, c = 805 m, and A  = 57°, we have;

a² = 410^2 + 805^2 - 2× 410×805×cos(57 degrees) = 456608.77 m²

a = The length of the stream = 675.73 m.

Answer:

x= -42

Step-by-step explanation:

put the liketerms together

x+35= -7

x=-35-7

note*the operation sign changes after crossing the equal sign

x= -42

[tex]1^4+1^2+1-k=0\\3-k=0\\k=3[/tex]

Answer:

k=3

Step-by-step explanation:

Hello, if p-1 is a factor of

[tex]f(p)=p^4+p^2+p-k[/tex]

it means that f(1)=0, so

1+1+1-k=0

3-k=0

k=3

thank you