-2(y-5)(-y+2)=0

Solution for -2(y-5)(-y+2)=0 equation:

-2(y-5)(-y+2)=0

We add all the numbers together, and all the variables

-2(y-5)(-1y+2)=0

We multiply parentheses ..

-2(-1y^2+2y+5y-10)=0

We multiply parentheses

2y^2-4y-10y+20=0

We add all the numbers together, and all the variables

2y^2-14y+20=0

a = 2; b = -14; c = +20;
Δ = b2-4ac
Δ = -142-4·2·20
Δ = 36
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{36}=6$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-14)-6}{2*2}=\frac{8}{4}
=2
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+6}{2*2}=\frac{20}{4}
=5
$