y+2y+y^2=-1

Solution for y+2y+y^2=-1 equation:

y+2y+y^2=-1

We move all terms to the left:

y+2y+y^2-(-1)=0

We add all the numbers together, and all the variables

y^2+3y+1=0

a = 1; b = 3; c = +1;
Δ = b2-4ac
Δ = 32-4·1·1
Δ = 5
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(3)-\sqrt{5}}{2*1}=\frac{-3-\sqrt{5}}{2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3)+\sqrt{5}}{2*1}=\frac{-3+\sqrt{5}}{2}
$