Imagine you are trying to maximize the calories you burn in a 60-minute workout you do a few times a week. running burns 9 calories per minute, aerobics burns 6 calories per minute, and rowing burns 7 calories per minute. you want to perform all three exercises to work different muscle groups. for the best effect, you need to run for at least 5 minutes and row for at least 15 minutes. and your aerobics session should be no more than 30 minutes. how many minutes should you perform each exercise to burn the maximum calories? write a system of inequalities based on the given constraints. then note the objective function