9x2=7x+8

Solution for 9x2=7x+8 equation:

9x^2=7x+8

We move all terms to the left:

9x^2-(7x+8)=0

We get rid of parentheses

9x^2-7x-8=0

a = 9; b = -7; c = -8;
Δ = b2-4ac
Δ = -72-4·9·(-8)
Δ = 337
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{337}}{2*9}=\frac{7-\sqrt{337}}{18}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7)+\sqrt{337}}{2*9}=\frac{7+\sqrt{337}}{18}
$