3(x-99)(x+70)=0

Solution for 3(x-99)(x+70)=0 equation:

3(x-99)(x+70)=0

We multiply parentheses ..

3(+x^2+70x-99x-6930)=0

We multiply parentheses

3x^2+210x-297x-20790=0

We add all the numbers together, and all the variables

3x^2-87x-20790=0

a = 3; b = -87; c = -20790;
Δ = b2-4ac
Δ = -872-4·3·(-20790)
Δ = 257049
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{257049}=507$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-87)-507}{2*3}=\frac{-420}{6}
=-70
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-87)+507}{2*3}=\frac{594}{6}
=99
$