Answer: -10x+7.5
Step-by-step explanation:
First multiply -2.5(4x)= -10x and then -2.5x-3= 7.5 it should be -10x+7.5
Answer:
Width = 
Step-by-step explanation:
All we have to do is to use the method of changing the subject. First we know that length * width is equal to area.
Area = length * width
We have the area and the length but we don't have the width. So we substitute the values we have int the equation and make the width (w) the subject.
(c^2 - 4x - 12) = (x + 2) * w
(c^2 - 4x - 12) = w(x +2)
Divide both sides by (x+2) so w can stand alone.

w = 
Answer:
19) n = -14
20) x = 4
21) b= -14
22) x = 2
23) x = -1
24) x = -9
Step-by-step explanation:
19) Use the distributive property to get rid of the parentheses. You will get: 20-4n = 76. So, n = -14.
20) Multiply both sides of the equation by 2 to get: -8 + x = -4. So, x = 4
21) Add 3 to both sides to get:
= -1. So, b = -14
22) Use the distributive property to get rid of the parentheses. You will get: -40 - 5x = -50. Then, add 40 to both sides to get: -5x = -10. So, x = 2.
23) Use the distributive property to get rid of the parentheses. You will get: -72 = -64 + 8x. Then, add 64 to both sides to get: -8 = 8x. So, x = -1
24) Add 2 to both sides to get:
= -3. So, x = -9
Hope this helps :)