The sum of an arithmetic series is found by multiplying the number of terms times the average of the first and last terms.
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Arithmetic Series.
Formula: or
Example: 3 + 7 + 11 + 15 + ··· + 99 has a1 = 3 and d = 4. To find n, use the explicit formula for an arithmetic sequence. We solve 3 + (n – 1)·4 = 99 to get n = 25.
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Answer:
The sum of an arithmetic series is found by multiplying the number of terms times the average of the first and last terms.
...
Arithmetic Series.
Formula: or
Example: 3 + 7 + 11 + 15 + ··· + 99 has a1 = 3 and d = 4. To find n, use the explicit formula for an arithmetic sequence. We solve 3 + (n – 1)·4 = 99 to get n = 25.
Step-by-step explanation:
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