the first club charges 100 dolars staarting fee and 10 dollars per movie so
100+10x
x represents how many times they go
second club 15x
so we want to find out whenthey will be equall so
100+10x=15x
subtract 10x from both sides
100=5x
divide both sides by 5
20=x
so you need to go 20 times to get the same value