Help with mathh please

Asystem of equations has 1 solution. if 4x-y=5 is one of the equations , which could be the other equation ?

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.

Could someone me with this question i’ve been stuck on it for 20 minutes