How to find out X in a trinomial How can I find out what X equals in this?
$$x^2 - 2x - 3 = 117$$
How would I get started? I'm truly stuck.

A different way if you have not seen the quadratic formula yet.
Recall that $(x-1)^2 = x^2-2x+1$ and so
$$
x^2-2x-3 = \left(x^2-2x+1\right)-4=(x-1)^2-4
$$
and your equation $120=x^2-2x-3$ becomes equivalent to
$$
117=(x-1)^2-4
$$
so $(x-1)^2 = 121 = 11^2$. Therefore, $x-1 = 11$ or $x-1 = -11$.
In the first case, $x = 11+1 = 12$.
In the second case, $x = -11+1 = -10$.
Check
In the first case, $x=12$ so $x^2-2x-3 = 144-24-3 = 117$.
In the second case, $x=-10$, so $x^2-2x-3 = 100+20-3 = 117$.
