0=-0.07x^2+x+2.2

Solution for 0=-0.07x^2+x+2.2 equation:

0=-0.07x^2+x+2.2

We move all terms to the left:

0-(-0.07x^2+x+2.2)=0

We add all the numbers together, and all the variables

-(-0.07x^2+x+2.2)=0

We get rid of parentheses

0.07x^2-x-2.2=0

We add all the numbers together, and all the variables

0.07x^2-1x-2.2=0

a = 0.07; b = -1; c = -2.2;
Δ = b2-4ac
Δ = -12-4·0.07·(-2.2)
Δ = 1.616
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{-(-1)-\sqrt{1.616}}{2*0.07}=\frac{1-\sqrt{1.616}}{0.14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+\sqrt{1.616}}{2*0.07}=\frac{1+\sqrt{1.616}}{0.14}
$