(12y+18)(1,6-0,2y)=0

Solution for (12y+18)(1,6-0,2y)=0 equation:

(12y+18)(1.6-0.2y)=0

We add all the numbers together, and all the variables

(12y+18)(-0.2y+1.6)=0

We multiply parentheses ..

(+0y^2+19.2y+0y+28.8)=0

We get rid of parentheses

0y^2+19.2y+0y+28.8=0

We add all the numbers together, and all the variables

y^2+20.2y+28.8=0

a = 1; b = 20.2; c = +28.8;
Δ = b2-4ac
Δ = 20.22-4·1·28.8
Δ = 292.84
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{-(20.2)-\sqrt{292.84}}{2*1}=\frac{-20.2-\sqrt{292.84}}{2}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20.2)+\sqrt{292.84}}{2*1}=\frac{-20.2+\sqrt{292.84}}{2}
$