(-5y-1,5)(0,3y+6,3)=0

Solution for (-5y-1,5)(0,3y+6,3)=0 equation:

(-5y-1.5)(0.3y+6.3)=0

We multiply parentheses ..

(+0y^2-31.5y-0y-9.45)=0

We get rid of parentheses

0y^2-31.5y-0y-9.45=0

We add all the numbers together, and all the variables

y^2-32.5y-9.45=0

a = 1; b = -32.5; c = -9.45;
Δ = b2-4ac
Δ = -32.52-4·1·(-9.45)
Δ = 1094.05
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$y_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-32.5)-\sqrt{1094.05}}{2*1}=\frac{32.5-\sqrt{1094.05}}{2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-32.5)+\sqrt{1094.05}}{2*1}=\frac{32.5+\sqrt{1094.05}}{2}
$