Question

for 15 weeks, sue put the same amount of money in a jar. then she took $9 out to spend on a friend's birthday present. she had $21 left. how much did she put in each week?

Answer 1

$2 because you add the 9 back to the 21 then divide by 15 to get 2

Answer 2

`x=amount\ she\ put\ in\ each\ week \\ 15x-9=21 \\ 15x=30 \\ x= (30)/(15) \\ x=2 \\ \boxed{2\ dollars\ each\ week}`