In place of x you keep 6 and in place of y you keep -2
1 is not. 2 is. 3 is not. 4 is. 5 is. 6 is. 7 is not. 8 is.
To find out how much is needed for 1 you will need to divide each given value by 4:
12 marshmallows / 4 = 3
8 graham crackers / 4 = 2
4 smores / 4 = 1
you then need to multiply each value by 3 :
3 marshmallows x 3 = 9
2 graham crackers x 3 = 6
1 smore x 3 = 3
therefore the answer would be :
9 marshmallows
6 graham crackers
hope this helps you