Question

A rectangular piece of plastic has an area of 30 square millimeters. Its perimeter is 26 millimeters. What are the dimensions of the piece of plastic?

Answer 1

L * w = 30 so L = 30/w
2 L + 2 w = 26

60/w + 2 w = 26
30 + w^2 = 13 w
w^2 -13 w + 30 = 0
(w - 10)(w+3) = 0
etc