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

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

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

We move all terms to the left:

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

We add all the numbers together, and all the variables

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

We multiply parentheses ..

-((+x^2+3x-11x-33))=0


We calculate terms in parentheses: -((+x^2+3x-11x-33)), so:

(+x^2+3x-11x-33)

We get rid of parentheses

x^2+3x-11x-33

We add all the numbers together, and all the variables

x^2-8x-33

Back to the equation:

-(x^2-8x-33)


We get rid of parentheses

-x^2+8x+33=0

We add all the numbers together, and all the variables

-1x^2+8x+33=0

a = -1; b = 8; c = +33;
Δ = b2-4ac
Δ = 82-4·(-1)·33
Δ = 196
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{196}=14$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-14}{2*-1}=\frac{-22}{-2}
=+11
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+14}{2*-1}=\frac{6}{-2}
=-3
$