(x)(x+8)=660

Solution for (x)(x+8)=660 equation:

(x)(x+8)=660

We move all terms to the left:

(x)(x+8)-(660)=0

We multiply parentheses

x^2+8x-660=0

a = 1; b = 8; c = -660;
Δ = b2-4ac
Δ = 82-4·1·(-660)
Δ = 2704
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2704}=52$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(8)-52}{2*1}=\frac{-60}{2}
=-30
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(8)+52}{2*1}=\frac{44}{2}
=22
$