X2+18x-115=0

Solution for X2+18x-115=0 equation:

X2+18X-115=0

We add all the numbers together, and all the variables

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