The independent variable for 3 would be how many hours are spent, while the dependant variable is how much is earned, the function would be y= 50x (total money, y, equals 50• hours worked), when 6 (for the hours) is plugged into the equation, y (total money earned) would be 300.
Question 7's independent variable is how many hours are worked, while the dependant variable is how much is earned, once again, it would mean y=17.75x (total money, y, is equal to 17.75, the price for each, multiplied by x, the amount sold). Which would mean that for 5 DVDs, the price would be 88.75