36=(x+9)(x+2)

Solution for 36=(x+9)(x+2) equation:

36=(x+9)(x+2)

We move all terms to the left:

36-((x+9)(x+2))=0

We multiply parentheses ..

-((+x^2+2x+9x+18))+36=0


We calculate terms in parentheses: -((+x^2+2x+9x+18)), so:

(+x^2+2x+9x+18)

We get rid of parentheses

x^2+2x+9x+18

We add all the numbers together, and all the variables

x^2+11x+18

Back to the equation:

-(x^2+11x+18)


We get rid of parentheses

-x^2-11x-18+36=0

We add all the numbers together, and all the variables

-1x^2-11x+18=0

a = -1; b = -11; c = +18;
Δ = b2-4ac
Δ = -112-4·(-1)·18
Δ = 193
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-11)-\sqrt{193}}{2*-1}=\frac{11-\sqrt{193}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-11)+\sqrt{193}}{2*-1}=\frac{11+\sqrt{193}}{-2}
$