y=5.5y-8.8y^2

Solution for y=5.5y-8.8y^2 equation:

y=5.5y-8.8y^2

We move all terms to the left:

y-(5.5y-8.8y^2)=0

We get rid of parentheses

8.8y^2-5.5y+y=0

We add all the numbers together, and all the variables

8.8y^2-4.5y=0

a = 8.8; b = -4.5; c = 0;
Δ = b2-4ac
Δ = -4.52-4·8.8·0
Δ = 20.25
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{-(-4.5)-\sqrt{20.25}}{2*8.8}=\frac{4.5-\sqrt{20.25}}{17.6}
$
$y_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4.5)+\sqrt{20.25}}{2*8.8}=\frac{4.5+\sqrt{20.25}}{17.6}
$