3(x+8)(x-2)=0

Solution for 3(x+8)(x-2)=0 equation:

3(x+8)(x-2)=0

We multiply parentheses ..

3(+x^2-2x+8x-16)=0

We multiply parentheses

3x^2-6x+24x-48=0

We add all the numbers together, and all the variables

3x^2+18x-48=0

a = 3; b = 18; c = -48;
Δ = b2-4ac
Δ = 182-4·3·(-48)
Δ = 900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{900}=30$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(18)-30}{2*3}=\frac{-48}{6}
=-8
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(18)+30}{2*3}=\frac{12}{6}
=2
$