-1.25x^2-0.75x+2=0

Solution for -1.25x^2-0.75x+2=0 equation:

-1.25x^2-0.75x+2=0

a = -1.25; b = -0.75; c = +2;
Δ = b2-4ac
Δ = -0.752-4·(-1.25)·2
Δ = 10.5625
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{-(-0.75)-\sqrt{10.5625}}{2*-1.25}=\frac{0.75-\sqrt{10.5625}}{-2.5}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.75)+\sqrt{10.5625}}{2*-1.25}=\frac{0.75+\sqrt{10.5625}}{-2.5}
$