Question

The area of a rectangle is 6x^3 – 30x^2. What is the length of the rectangle if the width is 2x(x – 5)?

Answer 1

So since the area of a rectangle is A=bh, we just need to form our equation off of that. Our equation will look like this:
`l*2x(x-5)=6x^3-30x^2`

Firstly, divide both sides by 2x(x-5):
`l=(6x^3-30x^2)/(2x(x-5))`

Next, factor 6x^3-30x^2:
`l=(6x^2(x-5))/(2x(x-5))`

Next, cancel out (x-5):
`l=(6x^2)/(2x)`

Next, expand 6x^2:
`l=(3*2*x^2)/(2x)`

Next, divide and your answer will be:
`l=3x`

Answer 2

x^2 + 8x +15 is the area

x+5 is the length

x+3 is the width

(x+5)(x+3)=

x^2 + 3x +5x +15

x^2 +8x + 15

Hope this helped!!!!