-2.2=9x-4.9x^2

Solution for -2.2=9x-4.9x^2 equation:

-2.2=9x-4.9x^2

We move all terms to the left:

-2.2-(9x-4.9x^2)=0

We get rid of parentheses

4.9x^2-9x-2.2=0

a = 4.9; b = -9; c = -2.2;
Δ = b2-4ac
Δ = -92-4·4.9·(-2.2)
Δ = 124.12
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{-(-9)-\sqrt{124.12}}{2*4.9}=\frac{9-\sqrt{124.12}}{9.8}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+\sqrt{124.12}}{2*4.9}=\frac{9+\sqrt{124.12}}{9.8}
$