-5(2y-15)4y=3

Solution for -5(2y-15)4y=3 equation:

-5(2y-15)4y=3

We move all terms to the left:

-5(2y-15)4y-(3)=0

We multiply parentheses

-40y^2+300y-3=0

a = -40; b = 300; c = -3;
Δ = b2-4ac
Δ = 3002-4·(-40)·(-3)
Δ = 89520
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:

$\sqrt{\Delta}=\sqrt{89520}=\sqrt{16*5595}=\sqrt{16}*\sqrt{5595}=4\sqrt{5595}$
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(300)-4\sqrt{5595}}{2*-40}=\frac{-300-4\sqrt{5595}}{-80}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(300)+4\sqrt{5595}}{2*-40}=\frac{-300+4\sqrt{5595}}{-80}
$