X2-88x-20=0

Solution for X2-88x-20=0 equation:

X2-88X-20=0

We add all the numbers together, and all the variables

X^2-88X-20=0

a = 1; b = -88; c = -20;
Δ = b2-4ac
Δ = -882-4·1·(-20)
Δ = 7824
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{7824}=\sqrt{16*489}=\sqrt{16}*\sqrt{489}=4\sqrt{489}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-88)-4\sqrt{489}}{2*1}=\frac{88-4\sqrt{489}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-88)+4\sqrt{489}}{2*1}=\frac{88+4\sqrt{489}}{2}
$