6(x+1)(2x-8)=0

Solution for 6(x+1)(2x-8)=0 equation:

6(x+1)(2x-8)=0

We multiply parentheses ..

6(+2x^2-8x+2x-8)=0

We multiply parentheses

12x^2-48x+12x-48=0

We add all the numbers together, and all the variables

12x^2-36x-48=0

a = 12; b = -36; c = -48;
Δ = b2-4ac
Δ = -362-4·12·(-48)
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-36)-60}{2*12}=\frac{-24}{24}
=-1
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-36)+60}{2*12}=\frac{96}{24}
=4
$