Please help me with these questions thank you

Identifying a Geometric Sequence In Exercises 7-16, determine whether or not the sequence is geometric. If it is, find the common ratio. 10. 1, -2, 4, -8, . 12. 5, 1, 0.2, 0.04, . 14. 9, -6, 4, -3, . 16. 2 2 3 4 5, 7, 9, 11, . Finding a Term of a Geometric Sequence In Exercises 39-42, find a formula for the nth term of the geometric Finding the Terms of a Geometric Sequence In Exercises sequence. Then find the indicated term of the geometric 17-24, write the first five terms of the geometric sequence. sequence. 18. a1 = 4, r = 2 39. 9th term: 7, 21, 63, . . . 20. a1 = 2, r = 3 40. 7th term: 3, 36, 432, . . . Finding a Term of a Geometric Sequence In Exercises 31-38, find the indicated term of the geometric sequence (a) using the table feature of a graphing utility and (b) algebraically. 31. a, = 6, r = 3, 12th term 32. a, = 24, r = 3, 8th termFinding the Sum of a Series In Exercises 117-120, find (a) the fourth partial sum and (b) the sum of the infinite series. OC k 117. 6(10) 118. 4 10 k = 1Sigma Notation for Sums In Exercises 87-98, find th sum. 5 87. (2i + 1) 88. (3i - 1) MAIM 89. 10 90. 4 k=1 IMu iMu iMu iMa 4 91. 12 92. 312 i=0 3 93. 94. K=OK + 1