X^2-8x+135-4x=180

Solution for X^2-8x+135-4x=180 equation:

X^2-8X+135-4X=180

We move all terms to the left:

X^2-8X+135-4X-(180)=0

We add all the numbers together, and all the variables

X^2-12X-45=0

a = 1; b = -12; c = -45;
Δ = b2-4ac
Δ = -122-4·1·(-45)
Δ = 324
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{324}=18$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-12)-18}{2*1}=\frac{-6}{2}
=-3
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-12)+18}{2*1}=\frac{30}{2}
=15
$