Answer:
Casey Bought 6 bags of chips
Step-by-step explanation:
If each sandwich costs 3 times the amount of a bag of chips and the sandwich is 6 dollars, the chips are 2 dollars. Casey bought 5 sandwiches and spent $30 dollars on sandwiches. Since the total was $42 dollars you have $12 dollars left to get your total of $42. 2x6 = 12 so therefore Casey bought 6 bags of chips.
Y=x-7 this is because you subtracted the x to both sides. Since y is a negative, you divide by -1 causing the -x to turn positive and the positive seven to be negative seven.