(4x-12)(x+11)=0

Solution for (4x-12)(x+11)=0 equation:

(4x-12)(x+11)=0

We multiply parentheses ..

(+4x^2+44x-12x-132)=0

We get rid of parentheses

4x^2+44x-12x-132=0

We add all the numbers together, and all the variables

4x^2+32x-132=0

a = 4; b = 32; c = -132;
Δ = b2-4ac
Δ = 322-4·4·(-132)
Δ = 3136
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3136}=56$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(32)-56}{2*4}=\frac{-88}{8}
=-11
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(32)+56}{2*4}=\frac{24}{8}
=3
$