X+x^2-8x-9=3

Solution for X+x^2-8x-9=3 equation:

X+X^2-8X-9=3

We move all terms to the left:

X+X^2-8X-9-(3)=0

We add all the numbers together, and all the variables

X^2-7X-12=0

a = 1; b = -7; c = -12;
Δ = b2-4ac
Δ = -72-4·1·(-12)
Δ = 97
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{-(-7)-\sqrt{97}}{2*1}=\frac{7-\sqrt{97}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+\sqrt{97}}{2*1}=\frac{7+\sqrt{97}}{2}
$