Question

Which of the following represents the area of a rectangle whose length is 5x − 3 and whose width is x + 7? 5x2 − 21 5x2 + 9x − 21 5x2 + 32x − 21 5x2 − 32x − 21

Answer 1

5x2 + 32x − 21

Explanation:

Answer 2

we know that

the area of the rectangle is equal to

`A=L*W`

where

L is the length side of the rectangle

W is the width side of the rectangle

In this problem we have

`L=(5x-3)\ units\\W=(x+7)\ units`

substitute the values in the formula above to find the area

`A=(5x-3)*(x+7)`

`A=(5x-3)*(x+7)\\A=5x*x+5x*7-3x-3*7\\A=5x^(2)+35x-3x-21\\A=5x^(2)+32x-21`

therefore

the answer is the option

5x2 + 32x − 21