y^2+2y=41.25

Solution for y^2+2y=41.25 equation:

y^2+2y=41.25

We move all terms to the left:

y^2+2y-(41.25)=0

We add all the numbers together, and all the variables

y^2+2y-41.25=0

a = 1; b = 2; c = -41.25;
Δ = b2-4ac
Δ = 22-4·1·(-41.25)
Δ = 169
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{169}=13$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-13}{2*1}=\frac{-15}{2}
=-7+1/2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+13}{2*1}=\frac{11}{2}
=5+1/2
$