It’s the first answer choice
Hope this helps
For sake of convenience, reverse the series, then it would be:
21,19,17.....7
a=21, d = -2,
s(4) = 4/2 (21+15)
s(4)=2(36)
s(4) = 72
Answer:
1/a^5
Step-by-step explanation:
a^-5=1/a^5
Top triangle((6X9)/2)=27square 7x9=63 parallelogram 7X9=69 right triangle ((7X6)/2)=21 so 27+63+63+21=174
