A. SOLVE THE FOLLOWING PROBLEMS ABOUT ARITHMETIC SEQUENCE AND ARITHMETIC SERIES ( SHOW YOUR SOLUTIONS) USE THE FORMULAS:
an = a1 + (-1)d for arithmetic sequence
Sn = n/2 (a1 + an) or Sn + n/2 {(2a1 + (n-1)d} for arithmetic series
I. ARITHMETIC SEQUENCE
1. 7th term of an arithmetic sequence given at first term is 3 (a1 + 3) and the commo difference is 4 (d = 4)
2. If a1 = 5 ; an = 450 and d = 5. find the value of N
3. The third is -20 and the 1th term is 44. What is the first term (a1)?
4. Find the 50th term of 5, 25, 45, 65, 85...
5. Find the 16th term of 5, 10, 15, 20...