x^2-1.1x-1.8=0

Solution for x^2-1.1x-1.8=0 equation:

x^2-1.1x-1.8=0

a = 1; b = -1.1; c = -1.8;
Δ = b2-4ac
Δ = -1.12-4·1·(-1.8)
Δ = 8.41
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{-(-1.1)-\sqrt{8.41}}{2*1}=\frac{1.1-\sqrt{8.41}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.1)+\sqrt{8.41}}{2*1}=\frac{1.1+\sqrt{8.41}}{2}
$