x^2-18x=115

Solution for x^2-18x=115 equation:

x^2-18x=115

We move all terms to the left:

x^2-18x-(115)=0

a = 1; b = -18; c = -115;
Δ = b2-4ac
Δ = -182-4·1·(-115)
Δ = 784
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{784}=28$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-18)-28}{2*1}=\frac{-10}{2}
=-5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-18)+28}{2*1}=\frac{46}{2}
=23
$