Question

What is the answer? x^2 + 4x - 6 = 0

Answer 1

First we have to find $\Delta$ from the equation $b^{2} -4ac$ where a, b and c are consecutive coefficients of the equation. In this case: $a=1, b=4, c=-6$

$\Delta =4^2-4*(-6)=16+24=40$, 

Later we will need to use $\sqrt{\Delta}$ sofor us $\sqrt{40}$. It can be then simplified to $2 \sqrt{10}$.

Then we use quadratic formula $x=\frac{-b\pm \sqrt{\Delta} }{2a}$ to see what are the options for x.

$x=\frac{-4\pm 2\sqrt{10}}{2}$
$x=- 2 \pm \sqrt{10}$

The answer for your question:
$x=- 2 + \sqrt{10}$ or $x=- 2 - \sqrt{10}$