2x squared - 24= x squared - 10x
If $\displaystyle n > 1$ in $\displaystyle x^n$ then you must get everything over to one side and the other side must equal zero.
$\displaystyle 2x^2 - 24 = x^2 - 10x$
$\displaystyle 2x^2 - x^2 + 10x - 24 = 0$
$\displaystyle x^2 + 10x - 24 = 0$
$\displaystyle (x + 12)(x - 2) = 0$
So $\displaystyle x = -12$ or $\displaystyle x = 2$