0=15x^2+5x

Solution for 0=15x^2+5x equation:

0=15x^2+5x

We move all terms to the left:

0-(15x^2+5x)=0

We add all the numbers together, and all the variables

-(15x^2+5x)=0

We get rid of parentheses

-15x^2-5x=0

a = -15; b = -5; c = 0;
Δ = b2-4ac
Δ = -52-4·(-15)·0
Δ = 25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25}=5$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-5}{2*-15}=\frac{0}{-30}
=0
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+5}{2*-15}=\frac{10}{-30}
=-1/3
$