Answer:
a = 19
Step-by-step explanation:
3a -1 = 2(a+9) . . . . . multiply by 8
3a -1 = 2a +18 . . . . . eliminate parentheses
a -1 = 18 . . . . . . . . . . subtract 2a
a = 19 . . . . . . . . . . . . add 1
