A **plot of land doubles in size** by **adding x meters to the length** **and x meters to the width** of the land. If **the original plot had an area of 200 by 300 meters**, what is the value of x?

Guest Apr 30, 2017

#1**+2 **

original area = a

a = 200 * 300

2a = (200 + x) * (300 + x)

Substitute in the value we know for a.

2(200 * 300) = (200 + x) * (300 + x)

Solve for x.

120,000 = 60,000 + 500x + x^{2}

60,000 = 500x + x^{2}

0 = x^{2} + 500x - 60,000

0 = (x - 100)(x + 600)

x = 100 or x = -600

Since the question says we are adding length, x must = 100

hectictar
Apr 30, 2017