Question

A rectangular red sticker has a perimeter of 12 millimeters and an area of 8 square millimeters. What are the dimensions of the sticker?

Answer 1

Answer: 9" by 7"

Step-by-step explanation:

let the dimensions of the rectangle be x and y

equation 1:  xy=63

equation 2:  2(x+y)=32

first, rearrange the terms

(1′):  y=63/x

(2′):  y=16−x

(1′)-(2′):  0=63/x−16+x

multiply the equation by  x

0=x2−16x+63

0=(x−9)(x−7)

so x = 7 or x = 9

from this, y = 9 when x = 7 and y = 7 when x = 9

so, the dimension of the rectangle is 9″ by 7″