15y^2-105y-270=0

Solution for 15y^2-105y-270=0 equation:

15y^2-105y-270=0

a = 15; b = -105; c = -270;
Δ = b2-4ac
Δ = -1052-4·15·(-270)
Δ = 27225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{27225}=165$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-105)-165}{2*15}=\frac{-60}{30}
=-2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-105)+165}{2*15}=\frac{270}{30}
=9
$