Betsy has a certain number of rings, r. the number of rings vivian has is 4 times as great. which expression can be used to determine the number of rings vivian has? a. r+4 b. 4-r c. ( don’t know how to write this, it’s a fraction.) r with a line under in with the number 4. d. 4r

The answer would be d 4r since you are trying to find the number of rings vivian has you would multiply the number of rings betsy has by 4

18 is one of the numbers that has 6 and 2 as its factors, but lacks 12 as one
A number with 12 as a factor has 6 and 2 as ones since 12 can be simplified to 6 times 2(60 for example has 12 times 5, while the 5 can't be simplified, 12 can and it simplifies to 6 times 2)