What is the percent of decrease from 100 to 61?

Which of these choices show a pair of equivalent expressions?

Hi i’m not sure how to do question 20 if u could explain how to do it that’d b great

In 1995 america online had about 3000000 users over the next decade users are expected to increase from a few million to the tens of millions suppose the number of users increased by 150% by the year 2000 how many users will there be in the year 2000