The perimeter of a rectangle is the same as the perimeter of a square. If the area of this rectangle
is x^2 + 4x – 21 and the side lengths are integers,
find:
a. the perimeter of the rectangle
b. the area of the square

a. 20

b. 25

Step-by-step explanation:

Let find the side lengths of the rectangle,

We can complete the square.

or

or

This means the perimeter of is

2 times -7 equal 14

2 times 3 equal 6

14+6=20.

The side lengths of the square is equal so each side length will measure 5.