I'm in calculus but there is a basic precalculus rule that I'm shady on and need to use.

If I had $\displaystyle y^2 = 3 - x $ and I wanted to solve for y, would I get y = +/- the square root of x - 3 ?

I forget if that is the proper situation when you have to use +/-

IF it is, then I need to set it equal to x - 1 and solve for x. How would that solve when the +/- is involved?