Answer:
a = 5.5
Step-by-step explanation:
3 (40 - 2) + 5 = 12a - 1
120 - 60 + 5 = 12a - 1
60 + 5 = 12a - 1
65 = 12a - 1
+1 +1
66 = 12a
/12 /12
5.5 = a