9x2=x+8

Solution for 9x2=x+8 equation:

9x^2=x+8

We move all terms to the left:

9x^2-(x+8)=0

We get rid of parentheses

9x^2-x-8=0

We add all the numbers together, and all the variables

9x^2-1x-8=0

a = 9; b = -1; c = -8;
Δ = b2-4ac
Δ = -12-4·9·(-8)
Δ = 289
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{289}=17$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-1)-17}{2*9}=\frac{-16}{18}
=-8/9
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1)+17}{2*9}=\frac{18}{18}
=1
$