2y+(y-1)*(y+1)=(y-1)*(y+1)

Solution for 2y+(y-1)*(y+1)=(y-1)*(y+1) equation:

2y+(y-1)(y+1)=(y-1)(y+1)

We move all terms to the left:

2y+(y-1)(y+1)-((y-1)(y+1))=0

We use the square of the difference formula

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

We add all the numbers together, and all the variables

2y^2+2y=0

a = 2; b = 2; c = 0;
Δ = b2-4ac
Δ = 22-4·2·0
Δ = 4
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4}=2$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2)-2}{2*2}=\frac{-4}{4}
=-1
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2)+2}{2*2}=\frac{0}{4}
=0
$