Answer:
a = -3
Step-by-step explanation:
−40 + 10a = -70
10a = -70 + 40
10a = -30
a = -30/10
a = -3
This is obviously a decreasing sequence. Thus, the common ratio is the fraction 1/4, not the integer 4. Eliminate C and D. Next, at n=1, the value of the 1st term is 16, which is actually 16(1/4)^(1-1) = 16(1) = 16. Thus, B is correct.
Answer:
47
Step-by-step explanation:
180 - 133 = 47