Let x represent the number of 6th graders in band. If there are 25% more in 7th grade, you can write it as (5/4)x. (You could also say 1.25x, but I think fractions would be easier in this situation.) Set up an equation:
Because had 8 but bought 9 more to where he then had 17 but if you take 8 times 2 then your answer is 16 and that's how many comic books he began with.
