9x^2-1-8x=0

Solution for 9x^2-1-8x=0 equation:

9x^2-1-8x=0

a = 9; b = -8; c = -1;
Δ = b2-4ac
Δ = -82-4·9·(-1)
Δ = 100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{100}=10$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-8)-10}{2*9}=\frac{-2}{18}
=-1/9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8)+10}{2*9}=\frac{18}{18}
=1
$