0=4x^2+5x-636

Solution for 0=4x^2+5x-636 equation:

0=4x^2+5x-636

We move all terms to the left:

0-(4x^2+5x-636)=0

We add all the numbers together, and all the variables

-(4x^2+5x-636)=0

We get rid of parentheses

-4x^2-5x+636=0

a = -4; b = -5; c = +636;
Δ = b2-4ac
Δ = -52-4·(-4)·636
Δ = 10201
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{10201}=101$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-101}{2*-4}=\frac{-96}{-8}
=+12
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+101}{2*-4}=\frac{106}{-8}
=-13+1/4
$