y^2=-2y+25

Solution for y^2=-2y+25 equation:

y^2=-2y+25

We move all terms to the left:

y^2-(-2y+25)=0

We get rid of parentheses

y^2+2y-25=0

a = 1; b = 2; c = -25;
Δ = b2-4ac
Δ = 22-4·1·(-25)
Δ = 104
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:

$\sqrt{\Delta}=\sqrt{104}=\sqrt{4*26}=\sqrt{4}*\sqrt{26}=2\sqrt{26}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2\sqrt{26}}{2*1}=\frac{-2-2\sqrt{26}}{2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2\sqrt{26}}{2*1}=\frac{-2+2\sqrt{26}}{2}
$