Answer:
width = 9 inches
Explanation:
let width be w then length is w + 12
the perimeter ( P) is calculated as
P = 2( width + length )
here P = 60 , then
2(w + w + 12) = 60 ( divide both sides by 2 )
2w + 12 = 30 ( subtract 12 from both sides )
2w = 18 ( divide both sides by 2 )
w = 9
that is the width of the rectangle is 9 inches