12x^2-120x+225=0

Solution for 12x^2-120x+225=0 equation:

12x^2-120x+225=0

a = 12; b = -120; c = +225;
Δ = b2-4ac
Δ = -1202-4·12·225
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-120)-60}{2*12}=\frac{60}{24}
=2+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-120)+60}{2*12}=\frac{180}{24}
=7+1/2
$