2y(y-30)=0

Solution for 2y(y-30)=0 equation:

2y(y-30)=0

We multiply parentheses

2y^2-60y=0

a = 2; b = -60; c = 0;
Δ = b2-4ac
Δ = -602-4·2·0
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-60)-60}{2*2}=\frac{0}{4}
=0
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-60)+60}{2*2}=\frac{120}{4}
=30
$