9.
15 + 9x-7
= 9
x x + 2
I'm assuming:
$\displaystyle \frac{15}{x} + \frac{9x-7}{x+2} = 9$
The common denominator is $\displaystyle (x)(x + 2)$, multiply every term by it.
$\displaystyle 15(x+2) + (9x-7)(x) = 9(x)(x + 2)$
$\displaystyle 15x + 30 + 9x^2 - 7x = 9x^2 + 18x$
$\displaystyle 15x + 30 - 7x + 9x^2 - 9x^2 - 18x = 0$
$\displaystyle -10x = - 30$
$\displaystyle x = 3$