Question

The perimeter of a rectangle is 18 feet, and the area of the rectangle is 20 square feet. What is the width of the rectangle?

Answer 1

4 ft or 5 ft

i think thats right

Answer 2

The width can be 5 ft or the width can be 4 ft

Explanation:

Perimeter = 2 (l+w) for a rectangle

Area = l*w for a rectangle

Using perimeter

18 = 2(l+w)

Divide by 2

18/2 = 2/2 (l+w)

9 = l+w

Solving for l

9-w = l

Using area

20 = l*w

Substituing for l

20 = (9-w) * w

20 = 9w - w^2

Subtract 20 from each side

20-20 =-w^2 +9w -20

0 = -w^2 +9w -20

Multiply by -1

0 = w^2 -9w+20

Factor

0 = (w-5) (w-4)

Using the zero product property

w-5 = 0 w-4 = 0

w= 5 w=4

The width can be 5 ft or the width can be 4 ft