(x)(x+2)=1680

Solution for (x)(x+2)=1680 equation:

(x)(x+2)=1680

We move all terms to the left:

(x)(x+2)-(1680)=0

We multiply parentheses

x^2+2x-1680=0

a = 1; b = 2; c = -1680;
Δ = b2-4ac
Δ = 22-4·1·(-1680)
Δ = 6724
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6724}=82$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-82}{2*1}=\frac{-84}{2}
=-42
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+82}{2*1}=\frac{80}{2}
=40
$