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.

Hint:1.$$ax^2 +bx +c=0 \to D=b^2-4ac\ge0 $$$$\ \to\begin{cases}
\color{green}{x_1=\frac{-b+\sqrt{D}}{2a}}  \\
\color{red}{x_2=\frac{-b-\sqrt{D}}{2a}} \\
\end{cases} $$$$$$ 2. $$x^2 +bx +c=(x+\frac{b}{2})^2=\frac{b^2}{4}-c\ge0\quad \text{then} x=\pm\sqrt{\frac{b^2}{4}-c}-\frac{b}{2}$$ 
3. find $x_1$and $x_2 $by solving following  system 
\begin{cases}
x_1+x_2=\frac{-b}{a}   \\
x_1x_2=\frac{c}{a} \\
\end{cases} 
