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2 years ago

What is ∑n=17(10n+90) equal to? Enter your answer in the box.

Mathematics

1 answer:

Illusion [34]2 years ago

6 0

Answer:

910

Step-by-step explanation:

$\sum_{n=1}^{7}(10n+90)\\\\=\sum_{n=1}^{7}(10n)+\sum_{n=1}^{7}(90)\\\\=10\sum_{n=1}^{7}(n)+90(7)\\\\=10(\frac{7(7+1)}{2})+630\\\\=10(28)+630\\\\=280+630\\\\=910$ <u />

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Step-by-step explanation:

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