y^2+28y+63=0

Solution for y^2+28y+63=0 equation:

y^2+28y+63=0

a = 1; b = 28; c = +63;
Δ = b2-4ac
Δ = 282-4·1·63
Δ = 532
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{532}=\sqrt{4*133}=\sqrt{4}*\sqrt{133}=2\sqrt{133}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(28)-2\sqrt{133}}{2*1}=\frac{-28-2\sqrt{133}}{2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(28)+2\sqrt{133}}{2*1}=\frac{-28+2\sqrt{133}}{2}
$