9514 1404 393
Answer:
7. c(n) = 10 +2(n -1)
8. c(20) = 48
Step-by-step explanation:
7. Your arithmetic sequence has first term a1=10 and constant difference d=2. The explicit formula for terms of an arithmetic sequence is ...
an = a1 +d(n -1)
If we use c(n) as the function name for the function giving the number of chairs in row n, then we can fill in the numbers we know to get ...
c(n) = 10 + 2(n -1)
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8. Evaluating the function when n=20, we find ...
c(20) = 10 +2(10-1) = 10 +2·19 = 10 +38
c(20) = 48
There are 48 chairs in row 20.
