- 21. Find the sum of the first 40 terms of the arithmetic sequence if the first term is 16 and the tenth term is 70.
A.) 5320
B) 1720
C) 2200
D) 6320
22. Find the sum of the first 15th terms of the arithmetic sequence whose nth term is an = 5 + 3n
A.) 870
B) 860
C) 435
D) 430
23. The first term of an arithmetic sequence is 8, the last term is 56 and the sum is 416. Find the number of terms.
A.) 13
B) 12
C) 11
D) 10 1.
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Answer:
21-b
22-à
23-b
Step-by-step explanation:
that is true
Answer:
sorry please ask your teacher
Step-by-step explanation:
sorry cary on learning