In the expression 2(10x) + 15y, x represents the number of hours Nina works in a week at a clothing store and y represents the number of hours she works in a week as a babysitter. The expression shows how much money Nina has earned this month. Which statement is true? Nina has worked a total of x – y hours so far this month. Nina works 15 hours a week at the clothing store. Nina makes 20x dollars at the clothing store each week. Nina makes $10 per hour babysitting each week.