Jin is deciding between two different movie streaming sites to subscribe to. plan a costs $6 per month plus $3 per movie watched. plan b costs $15 per month plus $2 per movie watched. let aa represent the monthly cost of plan a if jin watches xx per month, and let bb represent the monthly cost of plan b if jin watches xx movies per month. write an equation for each situation, in terms of x,x, and determine which plan would be cheaper if jin plans on watching 10 movies each month.