2x^2 - y^2 = 2xy
2x^2 = 2xy + y^2
(x+y)^2 = x^2 + y^2 + 2xy
we can substitute the value of y^2 + 2xy
(x+y)^2 = x^2 + 2x^2 = 3x^2
Hope this helps.
Simple Q
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Source: Beat The GMAT — Problem Solving |
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parallel_chase
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