2(x-y) times it by the conjugate: sqrt(x) + sqrt(y)
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sqrt(x) - sqrt(y) sqrt(x) + sqrt(y)
= 2x-2y (sqrt(x) + sqrt(y)) Now simplify: 2xsqrt(x) + 2xsqrt(y) - 2ysqrt(x) -2ysqrt(y)
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x - y x - y
2 (x (sqrt(x) + sqrt(y)) - y (sqrt(x) + sqrt(y))) Does that help?
