3x(x+60)=0

Solution for 3x(x+60)=0 equation:

3x(x+60)=0

We multiply parentheses

3x^2+180x=0

a = 3; b = 180; c = 0;
Δ = b2-4ac
Δ = 1802-4·3·0
Δ = 32400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{32400}=180$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(180)-180}{2*3}=\frac{-360}{6}
=-60
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(180)+180}{2*3}=\frac{0}{6}
=0
$