9x^2-9x-648=0

Solution for 9x^2-9x-648=0 equation:

9x^2-9x-648=0

a = 9; b = -9; c = -648;
Δ = b2-4ac
Δ = -92-4·9·(-648)
Δ = 23409
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{23409}=153$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-153}{2*9}=\frac{-144}{18}
=-8
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+153}{2*9}=\frac{162}{18}
=9
$