What is the value of y in the arithmetic sequence y + 6, 12, 3y?
Since the series is arithmetic (difference between terms is constant ), we can solve this :
12 - ( y + 6) = 3y -12 simplify
6 - y = 3y -12
6 + 12 = 4y
18 = 4y
y = 18/4 = 9/2
