2.5x^2=5.5x-2.2

Solution for 2.5x^2=5.5x-2.2 equation:

2.5x^2=5.5x-2.2

We move all terms to the left:

2.5x^2-(5.5x-2.2)=0

We get rid of parentheses

2.5x^2-5.5x+2.2=0

a = 2.5; b = -5.5; c = +2.2;
Δ = b2-4ac
Δ = -5.52-4·2.5·2.2
Δ = 8.25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5.5)-\sqrt{8.25}}{2*2.5}=\frac{5.5-\sqrt{8.25}}{5}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5.5)+\sqrt{8.25}}{2*2.5}=\frac{5.5+\sqrt{8.25}}{5}
$