y^2-y=1.25

Solution for y^2-y=1.25 equation:

y^2-y=1.25

We move all terms to the left:

y^2-y-(1.25)=0

We add all the numbers together, and all the variables

y^2-1y-1.25=0

a = 1; b = -1; c = -1.25;
Δ = b2-4ac
Δ = -12-4·1·(-1.25)
Δ = 6
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-\sqrt{6}}{2*1}=\frac{1-\sqrt{6}}{2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{6}}{2*1}=\frac{1+\sqrt{6}}{2}
$