Question

Question 3o Show all work.102i 3Find the sum ofsn (a1+an)

Answer 1

a1 is when i = 3. i.e. 2(3) + 3 = 6 + 3 = 9
an is when i = 10. i.e. 2(10) + 3 = 20 + 3 = 23
n = count from 3 to 10 = 8

Therefore, sum = 8/2(9 + 23) = 4(32) = 128