0=15x^2-64x+60

Solution for 0=15x^2-64x+60 equation:

0=15x^2-64x+60

We move all terms to the left:

0-(15x^2-64x+60)=0

We add all the numbers together, and all the variables

-(15x^2-64x+60)=0

We get rid of parentheses

-15x^2+64x-60=0

a = -15; b = 64; c = -60;
Δ = b2-4ac
Δ = 642-4·(-15)·(-60)
Δ = 496
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{496}=\sqrt{16*31}=\sqrt{16}*\sqrt{31}=4\sqrt{31}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(64)-4\sqrt{31}}{2*-15}=\frac{-64-4\sqrt{31}}{-30}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(64)+4\sqrt{31}}{2*-15}=\frac{-64+4\sqrt{31}}{-30}
$