.0055x^2-1.2x-9=0

Solution for .0055x^2-1.2x-9=0 equation:

.0055x^2-1.2x-9=0

a = .0055; b = -1.2; c = -9;
Δ = b2-4ac
Δ = -1.22-4·.0055·(-9)
Δ = 1.638
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{-(-1.2)-\sqrt{1.638}}{2*.0055}=\frac{1.2-\sqrt{1.638}}{0.011}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.2)+\sqrt{1.638}}{2*.0055}=\frac{1.2+\sqrt{1.638}}{0.011}
$