What is ungrouping in 3rd grade math?

In the diagram of circle o, what is the measure of zabc?

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.

Determine if the equation defines y as a function of x: 2xy = 1. yes o no