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

Solution for -2(y-1)(y-2)=0 equation:

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

We multiply parentheses ..

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

We multiply parentheses

-2y^2+4y+2y-4=0

We add all the numbers together, and all the variables

-2y^2+6y-4=0

a = -2; b = 6; c = -4;
Δ = b2-4ac
Δ = 62-4·(-2)·(-4)
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{-(6)-2}{2*-2}=\frac{-8}{-4}
=+2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6)+2}{2*-2}=\frac{-4}{-4}
=1
$