3. What is the value of m in the arithmetic sequence 2,_3m + 12 if arithmetic mean is 8?
A. 3
B. 2
C. ⅔
D.3/2

4. An arithmetic sequence has 5 as first term and -7 as the common difference. What is the sum of 5 terms?
A. -65
B. -55
C. -45
D. 45​