-0.129x^2+1.26x+1=0

Solution for -0.129x^2+1.26x+1=0 equation:

-0.129x^2+1.26x+1=0

a = -0.129; b = 1.26; c = +1;
Δ = b2-4ac
Δ = 1.262-4·(-0.129)·1
Δ = 2.1036
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{-(1.26)-\sqrt{2.1036}}{2*-0.129}=\frac{-1.26-\sqrt{2.1036}}{-0.258}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(1.26)+\sqrt{2.1036}}{2*-0.129}=\frac{-1.26+\sqrt{2.1036}}{-0.258}
$