I need help solving an equation

Question

Solve the following equation for a. Please show all of your work.
C = 1/6 (10b-7a)

Answer 1

C = 1/6 (10b-7a)
C = (1/6*10b) - (1/6*7a)
C = 5/3 b - 7/6 a
+7/6 a +7/6 a
C + 7/6 a = 5/3 b
-C -C
7/6 a = 5/3 b + C

Answer 2

oops not done.
(7/6 a) / 7/6 = (5/3 b + C)/ 7/6
a = (5/3 b + C)*(6/7)
a = 10/7 b + 6/7 C

Answer 3

multiply both sides by 6
6C = 10b - 7a
7a = 10b - 6C
a = (10/7)b - (6/7)C