Answers

2016-08-03T19:52:51+08:00
Let x be the width

Therefore,
W = x
L = x + 10

WL = 1200 
x (x + 10) = 1200
x^2 + 10x = 1200
x^2 + 10x - 1200 = 0
(x - 30)(x + 40)

x = -40
x = 30

Since, there is no negative dimension. Let's use x = 30

Thus, 

W = 30
L = 30 + 10 = 40

LW = 1200
(30)(40) = 1200

0