63-2y=y^2

Solution for 63-2y=y^2 equation:

63-2y=y^2

We move all terms to the left:

63-2y-(y^2)=0

determiningTheFunctionDomain
-y^2-2y+63=0

We add all the numbers together, and all the variables

-1y^2-2y+63=0

a = -1; b = -2; c = +63;
Δ = b2-4ac
Δ = -22-4·(-1)·63
Δ = 256
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{256}=16$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-2)-16}{2*-1}=\frac{-14}{-2}
=+7
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+16}{2*-1}=\frac{18}{-2}
=-9
$