x^2+2x=125

Solution for x^2+2x=125 equation:

x^2+2x=125

We move all terms to the left:

x^2+2x-(125)=0

a = 1; b = 2; c = -125;
Δ = b2-4ac
Δ = 22-4·1·(-125)
Δ = 504
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{504}=\sqrt{36*14}=\sqrt{36}*\sqrt{14}=6\sqrt{14}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-6\sqrt{14}}{2*1}=\frac{-2-6\sqrt{14}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+6\sqrt{14}}{2*1}=\frac{-2+6\sqrt{14}}{2}
$