Y=-x2+120x

Solution for Y=-x2+120x equation:

=-Y2+120Y

We move all terms to the left:

-(-Y2+120Y)=0

We add all the numbers together, and all the variables

-(-1Y^2+120Y)=0

We get rid of parentheses

1Y^2-120Y=0

We add all the numbers together, and all the variables

Y^2-120Y=0

a = 1; b = -120; c = 0;
Δ = b2-4ac
Δ = -1202-4·1·0
Δ = 14400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{14400}=120$
$Y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-120)-120}{2*1}=\frac{0}{2}
=0
$
$Y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-120)+120}{2*1}=\frac{240}{2}
=120
$