Question

sqrt(x-2)+sqrt(x+1)

Answer 1

sqrt(x-2)+sqrt(x+1)=x

Answer 2

\[\sqrt{x-2} + \sqrt{x+1} = x\]
Square both sides now.
You'll get

\[x-2+x+1+2\sqrt{(x-2)(x+1)} = x^2\]
\[2x -1+2\sqrt{x^2-x-2} = x^2\]

Now take the radical only, to one side, and then square again, to get rid of it.

You should find your solutions then.
You may get wrong solutions too, because of squaring, which may add extra roots, to verify, substitute them in your original equation. :)