y2+15y+36=0

Solution for y2+15y+36=0 equation:

y2+15y+36=0

We add all the numbers together, and all the variables

y^2+15y+36=0

a = 1; b = 15; c = +36;
Δ = b2-4ac
Δ = 152-4·1·36
Δ = 81
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{81}=9$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-9}{2*1}=\frac{-24}{2}
=-12
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+9}{2*1}=\frac{-6}{2}
=-3
$