x2+3.1x+1.3-12.22=0

Solution for x2+3.1x+1.3-12.22=0 equation:

x2+3.1x+1.3-12.22=0

We add all the numbers together, and all the variables

x^2+3.1x-10.92=0

a = 1; b = 3.1; c = -10.92;
Δ = b2-4ac
Δ = 3.12-4·1·(-10.92)
Δ = 53.29
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{-(3.1)-\sqrt{53.29}}{2*1}=\frac{-3.1-\sqrt{53.29}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3.1)+\sqrt{53.29}}{2*1}=\frac{-3.1+\sqrt{53.29}}{2}
$