-x^2-2.75x-0.75=0

Solution for -x^2-2.75x-0.75=0 equation:

-x^2-2.75x-0.75=0

We add all the numbers together, and all the variables

-1x^2-2.75x-0.75=0

a = -1; b = -2.75; c = -0.75;
Δ = b2-4ac
Δ = -2.752-4·(-1)·(-0.75)
Δ = 4.5625
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{-(-2.75)-\sqrt{4.5625}}{2*-1}=\frac{2.75-\sqrt{4.5625}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2.75)+\sqrt{4.5625}}{2*-1}=\frac{2.75+\sqrt{4.5625}}{-2}
$