How do to write 12.375 in expanded form

Will give brainliest series to sigma notation write the following series in sigma notation. 6+10+14+18+22+26+30 example image shown below.

Mr. thompson is on a diet. he currently weighs 260 pounds. he loses 4 pounds per month. what part of the story makes the relationship not proportional?

Acertain volume of water contains 100000 hydrogen atoms and 50,000 oxygen atoms how many hydrogen atoms are in a volume of water containing 4 million oxygen atoms