-5y(2y+30)+5=40

Solution for -5y(2y+30)+5=40 equation:

-5y(2y+30)+5=40

We move all terms to the left:

-5y(2y+30)+5-(40)=0

We add all the numbers together, and all the variables

-5y(2y+30)-35=0

We multiply parentheses

-10y^2-150y-35=0

a = -10; b = -150; c = -35;
Δ = b2-4ac
Δ = -1502-4·(-10)·(-35)
Δ = 21100
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:

$\sqrt{\Delta}=\sqrt{21100}=\sqrt{100*211}=\sqrt{100}*\sqrt{211}=10\sqrt{211}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-150)-10\sqrt{211}}{2*-10}=\frac{150-10\sqrt{211}}{-20}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-150)+10\sqrt{211}}{2*-10}=\frac{150+10\sqrt{211}}{-20}
$