-3y(5y+8)=0

Solution for -3y(5y+8)=0 equation:

-3y(5y+8)=0

We multiply parentheses

-15y^2-24y=0

a = -15; b = -24; c = 0;
Δ = b2-4ac
Δ = -242-4·(-15)·0
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-24)-24}{2*-15}=\frac{0}{-30}
=0
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-24)+24}{2*-15}=\frac{48}{-30}
=-1+3/5
$