8. order of operations: in each of the cases below, the actual numbers have been replaced by variables. write the number sentence that would correctly determine the answer. explain your reasoning for each problem. the students in the three fifth grade classes saved a cans, b cans, and c cans, respectively. if they received d cents per can, how much will they earn together? separately? emily has just gone to college. her cell phone will cost a dollar per month and her itunes account is b dollars per month. how much money will she spend during the c months of the college year? marissa has a dollars in her bank account. she babysat last week for a neighbor for b hours at a rate of c dollars per hour. she bought a cell phone for d dollars and spent e dollars on a dress. low much money does she have now? a. b. c.