So what do I do?? Like I can graph but there only one number

The fact that there is only one number is okay, just continue the way you usually would.

For example find two points:

when x=0: y=-3(0), y=0

when x=2: y=-3(2), y=-6

(0,0) and (2,-6) are two points on the line. Connect them and extend the line.

mr. flanders’ class sold 47 doughnuts and   mr. rodriquez’s class sold 38 cartons of milk

step-by-step explanation:

let x be the number of doughnuts sold by mr. flanders’ class and y be the number of cartons sold by mr. rodriquez’s class.

1. together, the classes sold 85 items, then

x+y=85.

2. both classes earn earned $104.49 for their school. if doughnuts were sold for $1.35 each, then x doughnuts costed $1.35x. if cartons of milk were sold for $1.08 each, then y cartons costed $1.08y. hence,

1.35x+1.08y=104.49.

3. solve the system of two equations: