0=15x^2-97x-56

Solution for 0=15x^2-97x-56 equation:

0=15x^2-97x-56

We move all terms to the left:

0-(15x^2-97x-56)=0

We add all the numbers together, and all the variables

-(15x^2-97x-56)=0

We get rid of parentheses

-15x^2+97x+56=0

a = -15; b = 97; c = +56;
Δ = b2-4ac
Δ = 972-4·(-15)·56
Δ = 12769
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{12769}=113$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(97)-113}{2*-15}=\frac{-210}{-30}
=+7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(97)+113}{2*-15}=\frac{16}{-30}
=-8/15
$