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

-1x^2+8x+33

Back to the equation:

-(-1x^2+8x+33)


We get rid of parentheses

1x^2-8x-33=0

We add all the numbers together, and all the variables

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