(9x-8)+(x+2)(x+10)=180

Solution for (9x-8)+(x+2)(x+10)=180 equation:

(9x-8)+(x+2)(x+10)=180

We move all terms to the left:

(9x-8)+(x+2)(x+10)-(180)=0

We get rid of parentheses

9x+(x+2)(x+10)-8-180=0

We multiply parentheses ..

(+x^2+10x+2x+20)+9x-8-180=0

We add all the numbers together, and all the variables

(+x^2+10x+2x+20)+9x-188=0

We get rid of parentheses

x^2+10x+2x+9x+20-188=0

We add all the numbers together, and all the variables

x^2+21x-168=0

a = 1; b = 21; c = -168;
Δ = b2-4ac
Δ = 212-4·1·(-168)
Δ = 1113
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{-(21)-\sqrt{1113}}{2*1}=\frac{-21-\sqrt{1113}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(21)+\sqrt{1113}}{2*1}=\frac{-21+\sqrt{1113}}{2}
$