3x2-27x+75=15

Solution for 3x2-27x+75=15 equation:

3x^2-27x+75=15

We move all terms to the left:

3x^2-27x+75-(15)=0

We add all the numbers together, and all the variables

3x^2-27x+60=0

a = 3; b = -27; c = +60;
Δ = b2-4ac
Δ = -272-4·3·60
Δ = 9
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{9}=3$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-27)-3}{2*3}=\frac{24}{6}
=4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-27)+3}{2*3}=\frac{30}{6}
=5
$