Question

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

Answer 1

100

Explanation:

The original area is (200 m)×(300 m) = 60000 m². You want an area that is ...

(200 +x)×(300 +x) = 120000

60000 +500x +x² = 120000 . . . . eliminate parentheses

x² +500x -60000 = 0 . . . . . . . . . . subtract 120000

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

The positive value of x that makes a factor zero is x = 100.

The value of x is 100.

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Check

The larger plot will be 300×400, the larger dimension being double the original smaller dimension.