Question

Find the 39th term of the arithmetic sequence

–66, - 68, – 70, ..
Answer:
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a boln. Video

Answer 1

-142

Explanation:

You seem to have an arithmetic sequence with first term -66 and common difference (-68-(-66)) = -2. The general term of such a sequence is given by ...

an = a1 +d(n -1) . . . . . for first term a1 and common difference d

We want to evaluate this equation for a1 = -66, d = -2, n = 39:

a39 = -66 -2(39 -1) = -66 -76 = -142

The 39th term is -142.