0=15x^2-7x-2

Solution for 0=15x^2-7x-2 equation:

0=15x^2-7x-2

We move all terms to the left:

0-(15x^2-7x-2)=0

We add all the numbers together, and all the variables

-(15x^2-7x-2)=0

We get rid of parentheses

-15x^2+7x+2=0

a = -15; b = 7; c = +2;
Δ = b2-4ac
Δ = 72-4·(-15)·2
Δ = 169
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{169}=13$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(7)-13}{2*-15}=\frac{-20}{-30}
=2/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(7)+13}{2*-15}=\frac{6}{-30}
=-1/5
$