Problem 4
Answer: Choice C) store 1 is $0.75 less per pound compared to store 2
--------------------
Explanation:
The equation y = 6.75x shows that the cost of 1 steak is $6.75 per pound, when you buy from store 1. This is the unit cost.
The table shows the unit cost of store 2 is 15/2 = 7.50 dollars per pound. Simply pick any row from the table, and divide the y over x value. So k = y/x is the unit cost. It's also the constant of proportionality.
From here, we subtract the two unit costs: 7.50 - 6.75 = 0.75
The unit cost at store 1 is 0.75 dollars less than the unit cost of store 2.
=======================================================
Problem 5
Answer: 2.4 necklaces
--------------------
Explanation:
4/5 of a necklace = 20 minutes
3*(4/5 of a necklace) = 3*(20 minutes) ..... multiply both sides by 3
12/5 of a necklace = 60 minutes
12/5 of a necklace = 1 hour
Use your calculator to find that 12/5 = 2.4