Question
The 10th and 10th terms of an Ap is -27 and -12, what is the 18th term, find the sum of its 25 terms
Answers
oobleck
The 10th and 10th terms ... ???
after you fix your typo and solve for a and d, then
a_18 = a+17d
S25 = 25/2 (2a + 24d)
after you fix your typo and solve for a and d, then
a_18 = a+17d
S25 = 25/2 (2a + 24d)