Question

the length of a rectangular piece of land is 12cm more than four times its width. the perimeter is 74cm. find its dimensions

Answer 1

length = 32 and width = 5

let the width = w then length = 4w + 12

perimeter = 2 ( length + width )

               = 2( 4w + 12 + w ) = 2( 5w + 12 ) = 10w + 24

perimeter = 74

solve 10w + 24 = 74

subtract 24 from both sides

10w = 74 - 24 = 50 ⇒ w = 5

width = 5 and length = (4 × 5) + 12 = 20 + 12 = 32