300 students are going on a school trip and 16 adults will accompany them. The head teacher needs to hire coaches to take them on the trip. She can hire small coaches that seat 20 people or large coaches that seat 48 people. There must be at least 2 adults on each coach to supervise the students. a )If x is the number of small coaches hired and y is the number of large coaches, explain why these inequalities model the situation.
x⩾0
y⩾0
5x+12y⩾79
x+y⩽8
b)Show the region on a graph that satisfies all four inequalities.​