Need help math with it

Can someone me do math because i am having a breakdown rn because i don’t get it

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible

The functions below show the amount of money bella and sweet t had saved after earning money for doing chores. which description best compares the two functions?