136=(x+17)(x-12)

Solution for 136=(x+17)(x-12) equation:

136=(x+17)(x-12)

We move all terms to the left:

136-((x+17)(x-12))=0

We multiply parentheses ..

-((+x^2-12x+17x-204))+136=0


We calculate terms in parentheses: -((+x^2-12x+17x-204)), so:

(+x^2-12x+17x-204)

We get rid of parentheses

x^2-12x+17x-204

We add all the numbers together, and all the variables

x^2+5x-204

Back to the equation:

-(x^2+5x-204)


We get rid of parentheses

-x^2-5x+204+136=0

We add all the numbers together, and all the variables

-1x^2-5x+340=0

a = -1; b = -5; c = +340;
Δ = b2-4ac
Δ = -52-4·(-1)·340
Δ = 1385
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{-(-5)-\sqrt{1385}}{2*-1}=\frac{5-\sqrt{1385}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+\sqrt{1385}}{2*-1}=\frac{5+\sqrt{1385}}{-2}
$