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?
(1) Answers
The area of the original plot is 200 x 300 = 60000 So the problem says (x + 200)(x + 300) = 120000 Proof: 300 x 400 = 120000 x^2 + 500x + 60000 = 120000 x^2 + 500x - 60000 = 0 (x + 600)(x - 100) = 0, so x = - 600 (reject), x = 100 So x = 100 meters Proof: 300 x 400 = 120000
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