Please answer all questions (#40-43). Show all work. I will mark as helpful when completed.

Find the sum of the following series. (hint: use the formula for arithmetic sequences first to find n) 36. 5, 9, 13, ..., 101 37. 83, 80, 77, ..., 5 38. -17, -12, -7,..., 33 39. 1, 1 1/4 , 1 1/2, ... 9 3/4 Find the sum of the following series. 40. 8, 11, ... to 16 terms 41. 3, 8 1/2, ... to 21 terms 42. 19, 13, ... to 10 terms 43. -9, -1, ... to 8 terms