9514 1404 393
Answer:
a9 = -8 +9(9 -1)
Explanation:
The given sequence has a common difference of 1-(-8) = 10-1 = 9, and a first term of -8. The formula for the n-th term of such an arithmetic sequence is ...
an = a1 +d(n -1) . . . . . first term a1, common difference d
For the parameter of this sequence, a1=-8 and d=9, the n-th term is ...
an = -8 +9(n -1) . . . . formula for the n-th term
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Then the formula for the 9th term is ...
a9 = -8 +9(9 -1)