What is the answer. I really don't know?

The variable z is directly proportional to x, and inversely proportional to y. when x is 4 and y is 13, z has the value 1.2307692307692. what is the value of z when x= 9, and y= 20

What is the domain and range of each function 1. x (3, 5, 7, 8, 11) y ( 6, 7, 7, 9, 14) 2. x (-3, -1, 2, 5, 7) y (9, 5, 4, -5, -7)

Tom is the deli manager at a grocery store. he needs to schedule employee to staff the deli department for no more that 260 person-hours per week. tom has one part-time employee who works 20 person-hours per week. each full-time employee works 40 person-hours per week. write and inequality to determine n, the number of full-time employees tom may schedule, so that his employees work on more than 260 person-hours per week. graph the solution set to this inequality.