You and a friend both work two different jobs. the system of linear equations represents the total earnings for x hours worked at the first job and y hours worked at the second job. your friend earns twice as much as you.

a) one week, both of you work 4 hours at the first job. how many hours do you and your friend work at the second job?

b) both of you work the same number of hours at the second job. compare the number of hours each of you works at the first job.

Ascientist places 24 cells in a petri dish. she knows the cells grow at an exponential rate, doubling in number every hour. how long will it take (in hours) for there to be 1100 cells in the dish? time to 1100 cells: 5.51832530 hours how long will it take to reach 110 cells? time to 110 cells : 2.1963972 hours what is the average rate of change in the number of cells between 9 hours and 11 hours? average rate of change: cells per hour what is the instantaneous rate of change after 7 hours? instantaneous rate of change: cells per hour note: you can earn partial credit on this problem.