The equation for Dan would be 35 + 4x = y, in which 35 is the membership fee and 4 is the amount it costs to rent a game. Based on that same logic, the equation for Barney would be 30 + 3x = y (if you rewrite it), in which case the membership fee would be 30 and 3 would be the amount it costs to rent a game. And since 35 - 30 = 5, that means that there is a five dollar difference between Dan and Barney's membership fees.
