2t(15t-60)=0

Solution for 2t(15t-60)=0 equation:

2t(15t-60)=0

We multiply parentheses

30t^2-120t=0

a = 30; b = -120; c = 0;
Δ = b2-4ac
Δ = -1202-4·30·0
Δ = 14400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{14400}=120$
$t_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-120)-120}{2*30}=\frac{0}{60}
=0
$
$t_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-120)+120}{2*30}=\frac{240}{60}
=4
$