15x^2-75x+90=0

Solution for 15x^2-75x+90=0 equation:

15x^2-75x+90=0

a = 15; b = -75; c = +90;
Δ = b2-4ac
Δ = -752-4·15·90
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-75)-15}{2*15}=\frac{60}{30}
=2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-75)+15}{2*15}=\frac{90}{30}
=3
$