(X-11)(x-2)=0

Solution for (X-11)(x-2)=0 equation:

(X-11)(X-2)=0

We multiply parentheses ..

(+X^2-2X-11X+22)=0

We get rid of parentheses

X^2-2X-11X+22=0

We add all the numbers together, and all the variables

X^2-13X+22=0

a = 1; b = -13; c = +22;
Δ = b2-4ac
Δ = -132-4·1·22
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-13)-9}{2*1}=\frac{4}{2}
=2
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-13)+9}{2*1}=\frac{22}{2}
=11
$