Simple Algebra 2 problem

Hey i have a final reveiw for my advanced algebra 2/ trig class, and i forgot how to do this problem:

it's
square root x+12= x
what are the solutions?

-3
4,-3
4
no solution

how do i do this??

sqrt(x + 12) = x if I read this right.

square both sides giving x + 12 = x^2

Bring x + 12 to the other side to get 0 = x^2 - x - 12

simplify by factorin to get 0 = (x + 3)(x - 4)

x = -3 and 4

first, you have to square the question so it would look like:
(square root x+12)SQUARED= xSQUARED
that will take out the square root sign, so it will just be:
x+12= xSQUARED
then, subtract x+12 from both sides, to get them on the same side as the the xSQUARED, so it will now look like this:
xSQUARED - x - 12= 0
then do the diamond thingy to factor and you'll get -4 and 3 as answers. But those are NOT the true answers, because they are on the other side of the zero, so you must subtract them, like so:
(x-4)+(x+3)= 0
+4 -3 +4 -3
x=4, x=-3
so the second answer you had is the correct one, 4, -3.