Question 591662
Do it like this one.
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How do you solve: 

(√x^2+7) - x = 7
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Isolate the radical, then square both sides
{{{sqrt(x^2+7) - x = 7}}}
{{{sqrt(x^2+7) = x + 7}}}
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{{{x^2 + 7 = x^2 + 14x + 49}}}
etc