-5y(180+5y)=180

Solution for -5y(180+5y)=180 equation:

-5y(180+5y)=180

We move all terms to the left:

-5y(180+5y)-(180)=0

We add all the numbers together, and all the variables

-5y(5y+180)-180=0

We multiply parentheses

-25y^2-900y-180=0

a = -25; b = -900; c = -180;
Δ = b2-4ac
Δ = -9002-4·(-25)·(-180)
Δ = 792000
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{792000}=\sqrt{14400*55}=\sqrt{14400}*\sqrt{55}=120\sqrt{55}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-900)-120\sqrt{55}}{2*-25}=\frac{900-120\sqrt{55}}{-50}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-900)+120\sqrt{55}}{2*-25}=\frac{900+120\sqrt{55}}{-50}
$