Question

im having trouble with this one.
Find the 15th term of the sequence in which a1 = -11 and the common difference is -6.
with the equation i have im getting -795, and thats not right

Answer 1

nth term of an arithmetic sequence is given as
\[a_n=a_1+(n-1)d\]
\(a_1\)= first term
d= common difference
here
\(a_1\)=-11
d=-6
n=15
\[a_{15}=a_1+(15-1)d\]
\[a_{15}=-11+(14)\times (-6)\]
Now you evaluate and check if it matches the answer?

Answer 2

the answer would be -95 then

Answer 3

Yeah:D

Answer 4

awesome! thanks a lot!!! now i was given an equation earlier that had me divide by 2 in the begining, does that mean i have the incorrect answers?

Answer 5

What equation you had? Can you post the equation?

Answer 6

s=n/2(2a+(n-1)d)

Answer 7

That's for the sum of the sequence. It's correct but not applicable here

Answer 8

ok i see, thanks again ! :D

Answer 9

Welcome:D