Question

given the terms a1 = 5 and a 4= 14 of an arithmetic sequence what is a20

Answer 1

\[T _{20}=a _{1}+(n-1)d\] we need d

Answer 2

now, \[a _{4}=a _{1}+(n-1)d, a _{4}=5+(4-1)d, 14=5+(3)d\] find d and you will have T 20 :)

Answer 3

\[T _{20}=5+(20-1)d\]

Answer 4

wait..... it is multiple choice it could be 62, 65,171, 185

Answer 5

well calculate it :) your d=3 i guess then put d in the equation and find it :)

Answer 6

wait what?? so t20=5+(19)3

Answer 7

correct

Answer 8

I got 62

Answer 9

thats the answer :)

Answer 10

awesome thank you!!! can you help me with more!!! i am so behind in my math class!

Answer 11

keep posting :) don't follow up