Ahealth club chargers non-members $5 per day to swim and $9 per day for an exercise class. members pay a yearly fee of $300 plus $4 per day to attend an exercise class and no swim fee. if robert swims and takes an exercise class every time he goes to the gym, which equation shows the number of days, d, he must use the gym to make the membership worthwhile?
5d+9d
= 4d
300
5d+9d
=300
4d
5d+9d=300-4d
5d+9d=300+4d