Suppose tuna is on sale for $0.90 a can, and you have a coupon for $0.40 off your total purchase. Write a function rule for the cost of n cans of tuna.
AC(n)=0.90n-0.40
BC(n)=0.40n-0.90
CC(n)=(0.90+n)-0.40
DC(n)=(0.40+n)-0.90
AC(n)=0.90n-0.40
BC(n)=0.40n-0.90
CC(n)=(0.90+n)-0.40
DC(n)=(0.40+n)-0.90