-1.1x^2-1.3x+4.7=0

Solution for -1.1x^2-1.3x+4.7=0 equation:

-1.1x^2-1.3x+4.7=0

a = -1.1; b = -1.3; c = +4.7;
Δ = b2-4ac
Δ = -1.32-4·(-1.1)·4.7
Δ = 22.37
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{-(-1.3)-\sqrt{22.37}}{2*-1.1}=\frac{1.3-\sqrt{22.37}}{-2.2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.3)+\sqrt{22.37}}{2*-1.1}=\frac{1.3+\sqrt{22.37}}{-2.2}
$