(80-y)(y)=0

Solution for (80-y)(y)=0 equation:

(80-y)(y)=0

We add all the numbers together, and all the variables

(-1y+80)y=0

We multiply parentheses

-1y^2+80y=0

a = -1; b = 80; c = 0;
Δ = b2-4ac
Δ = 802-4·(-1)·0
Δ = 6400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{6400}=80$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(80)-80}{2*-1}=\frac{-160}{-2}
=+80
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(80)+80}{2*-1}=\frac{0}{-2}
=0
$