Actually, x2 - 12 cannot be simplified.
5 or 12
x squared minus 12 x plus 36 = (x - 6)(x - 6)
It is x^2 -x -12 is (x+3)(x-4) when factored
There is nothing to "do".
This expression factors as x -1 quantity squared.
y2-12=5x is an equation. When graphed, it is a parabola.
X= plus or minus 1
It is impossible but if it were x squared plus 2x minus 15 the equation would be (x+5) (x-3) with x being equal to either -5 or 3. If the original problem was x squared minus 2x minus 15 the equation would be (x-5)(x+3) and x would be equal to either 5 or -3
x = 1
x = ? 42 = x squared minus x
12 squared (12 x 12) = 144
(x - 12)(x + 12)