Answer:
[tex]y = -\frac{1}{15} a + \frac{2}{3}[/tex]
Step-by-step explanation:
3a + 15y - 5a = -a + 2(3 - a)
-2a + 15y = -a + 6 - 2a
-2a + 15y = -3a + 6
15y = -a + 6
y = -1/15a + 2/3