x+(x+70)(x+20)=180

Solution for x+(x+70)(x+20)=180 equation:

x+(x+70)(x+20)=180

We move all terms to the left:

x+(x+70)(x+20)-(180)=0

We multiply parentheses ..

(+x^2+20x+70x+1400)+x-180=0

We get rid of parentheses

x^2+20x+70x+x+1400-180=0

We add all the numbers together, and all the variables

x^2+91x+1220=0

a = 1; b = 91; c = +1220;
Δ = b2-4ac
Δ = 912-4·1·1220
Δ = 3401
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{-(91)-\sqrt{3401}}{2*1}=\frac{-91-\sqrt{3401}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(91)+\sqrt{3401}}{2*1}=\frac{-91+\sqrt{3401}}{2}
$