X^2+9x=135

Solution for X^2+9x=135 equation:

X^2+9X=135

We move all terms to the left:

X^2+9X-(135)=0

a = 1; b = 9; c = -135;
Δ = b2-4ac
Δ = 92-4·1·(-135)
Δ = 621
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:

$\sqrt{\Delta}=\sqrt{621}=\sqrt{9*69}=\sqrt{9}*\sqrt{69}=3\sqrt{69}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(9)-3\sqrt{69}}{2*1}=\frac{-9-3\sqrt{69}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(9)+3\sqrt{69}}{2*1}=\frac{-9+3\sqrt{69}}{2}
$