Question 253865
{{{sqrt(x-5)-sqrt(x)=-2}}}
Square both sides:
{{{(x-5) + x - 2sqrt(x^2-5x) = 4}}}
{{{2x-9 = 2sqrt(x^2-5x)}}}
Square again
{{{4x^2 - 36x + 81 = 4x^2-20x}}}
{{{- 16x +81 = 0}}}
16x = 81
x = 81/16
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There are no extraneous solutions.