X2-9x-136=0

Solution for X2-9x-136=0 equation:

X2-9X-136=0

We add all the numbers together, and all the variables

X^2-9X-136=0

a = 1; b = -9; c = -136;
Δ = b2-4ac
Δ = -92-4·1·(-136)
Δ = 625
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{625}=25$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-25}{2*1}=\frac{-16}{2}
=-8
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+25}{2*1}=\frac{34}{2}
=17
$