0=20x^2+28x-3

Solution for 0=20x^2+28x-3 equation:

0=20x^2+28x-3

We move all terms to the left:

0-(20x^2+28x-3)=0

We add all the numbers together, and all the variables

-(20x^2+28x-3)=0

We get rid of parentheses

-20x^2-28x+3=0

a = -20; b = -28; c = +3;
Δ = b2-4ac
Δ = -282-4·(-20)·3
Δ = 1024
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1024}=32$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-28)-32}{2*-20}=\frac{-4}{-40}
=1/10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-28)+32}{2*-20}=\frac{60}{-40}
=-1+1/2
$