(x-4)(3x+11)=0

Solution for (x-4)(3x+11)=0 equation:

(x-4)(3x+11)=0

We multiply parentheses ..

(+3x^2+11x-12x-44)=0

We get rid of parentheses

3x^2+11x-12x-44=0

We add all the numbers together, and all the variables

3x^2-1x-44=0

a = 3; b = -1; c = -44;
Δ = b2-4ac
Δ = -12-4·3·(-44)
Δ = 529
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{529}=23$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-23}{2*3}=\frac{-22}{6}
=-3+2/3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+23}{2*3}=\frac{24}{6}
=4
$