The perimeter of a rectangle is 58 inches . find the width of the rectangle if the lengh is 20 in

The width of the rectangle is 9 inches.

Step-by-step explanation:

The formula of perimeter is Perimeter = 2·length + 2·width. The length is 20. If we call "x" to the width.

Perimeter = 2·(20) + 2·x ⇒ Perimeter = 40 + 2x ⇒ 58 =40 + 2x ⇒

58 -40 =2x ⇒ 18 = 2x ⇒18/2 = x ⇒ 9 = x.

The width of the rectangle is 9 inches.

answer:   x = 3 + √11     and     x = 3 - √11

step-by-step explanation:

x² - 6x + 9 = 11

(x - 3)² = 11

x - 3 = ±√11

    x = 3 ± √11

x = 3 + √11     and     x = 3 - √11