X2-2x-8.75x-2=0

Solution for X2-2x-8.75x-2=0 equation:

X2-2X-8.75X-2=0

We add all the numbers together, and all the variables

X^2-10.75X-2=0

a = 1; b = -10.75; c = -2;
Δ = b2-4ac
Δ = -10.752-4·1·(-2)
Δ = 123.5625
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{-(-10.75)-\sqrt{123.5625}}{2*1}=\frac{10.75-\sqrt{123.5625}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10.75)+\sqrt{123.5625}}{2*1}=\frac{10.75+\sqrt{123.5625}}{2}
$