Question

What is the sum of a 22-term arithmetic sequence where the first term is 54 and the last term is -30?
Select one:
A. 264
B. 288
C. 312
D. 336

Answer 1

the sum eq for arith is Sn=n(t1+t2)/2
n= how many terms there are (22)
t1= first term
tn= last term
it's basically a plug and chug problem

Answer 2

I don't know how that works

Answer 3

So you put in Sn= 22(54+ -30)/2
Simplify... Sn= 22(24)/2
The answer... Sn= 264