-y^2-9y+15=29

Solution for -y^2-9y+15=29 equation:

-y^2-9y+15=29

We move all terms to the left:

-y^2-9y+15-(29)=0

We add all the numbers together, and all the variables

-1y^2-9y-14=0

a = -1; b = -9; c = -14;
Δ = b2-4ac
Δ = -92-4·(-1)·(-14)
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{-(-9)-5}{2*-1}=\frac{4}{-2}
=-2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+5}{2*-1}=\frac{14}{-2}
=-7
$