Katie and Tom are selling pens. Katie makes a dollar for every two pens she sells and has $5 that she made yesterday. Tom makes $2 for every three pens he sells and he owes the teacher $4 from yesterday. After selling pens all day, they have the same amount of money. Using the equation below, how many pens did they sell?
1/2x+5=2/3x−4
9
45/2
54
3