x(X+9)=118

Solution for x(X+9)=118 equation:

x(x+9)=118

We move all terms to the left:

x(x+9)-(118)=0

We multiply parentheses

x^2+9x-118=0

a = 1; b = 9; c = -118;
Δ = b2-4ac
Δ = 92-4·1·(-118)
Δ = 553
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-\sqrt{553}}{2*1}=\frac{-9-\sqrt{553}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+\sqrt{553}}{2*1}=\frac{-9+\sqrt{553}}{2}
$