Step-by-step explanation:
[tex] \frac{2}{3} (a - 9) - \frac{1}{6} ( - 2a + 18)[/tex]
[tex] = \frac{2a - 18}{3} - \frac{2a - 18}{6} \\ = \frac{2a - 18 - (6a - 54)} 6[/tex]
[tex] = \frac{2a - 18 - 6a + 54}{6}\\= \frac{ - 4a + 36}{6} \\ = \frac{4( - a + 9)}{6} \\ = \frac{2( - a + 9)}{3} [/tex]
