y2+17y+66=0

Solution for y2+17y+66=0 equation:

y2+17y+66=0

We add all the numbers together, and all the variables

y^2+17y+66=0

a = 1; b = 17; c = +66;
Δ = b2-4ac
Δ = 172-4·1·66
Δ = 25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25}=5$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(17)-5}{2*1}=\frac{-22}{2}
=-11
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(17)+5}{2*1}=\frac{-12}{2}
=-6
$