leslie can buy an 8-poundd bag of dog food for 7.40 or a 4-pound bag of the same dog food for 5.38 which is the better buy useing and number line

Answer 1

740/8 = 92 1/2 cents per pound for the 8lbs for $7.40 option

538/4 = $1.34 and half a cent per pound for 4lbs at $5.38

the 8 pound deal is better,

usually there is some kind of volume discount

8 lbs cost $10.76 with 2 4 lb. bags

8 lbs cost $7.40 with 1 8 lb. bag

one 8 lb bag is cheapest, saving $3.36 if you need 8 lbs.

but

if all you need is 4 pounds, then you threw away $2.02 by buying the one 8 lb bag

the 8 pound bag is definitely a better deal if you need 16 or more pounds, and if you just bought a 4 pound bag, then waited until later to buy more, with inflation the price may be much higher or with food shortages not even available.