Question

How can you use a pattern to add 20+30+40+50+60+70+80​

Answer 1

`\displaystyle \: \: \: \: 7 \\ \: \: \sum \: (10n + 10) \\ n = 1`

Explanation:

You can use Summation Notation as a pattern to evaluating "20 + 30 + 40 + 50 + 60 + 70 + 80":

`\displaystyle \: \: \: \: 7 \\ \: \: \sum \: (10n + 10) \\ n = 1`

I am joyous to assist you anytime.