Answer:
[tex]\frac{-1}{3}a + \frac{5}{6} +2\frac{1}{6} -\frac{5}{6}a\\\\\frac{-1}{3}a + \frac{5}{6} +\frac{13}{6} -\frac{5}{6}a\\\\\frac{-2a + 5 + 13-5a}{6}\\\\\frac{-7a +18}{6}[/tex]