Answer: 3 Sets of the 4 post cards and 3 of the single post cart sets.
Step-by-step explanation:
You buy 3 of the 4 post card set becuase that is the most you can get of those to get under 15 post cards.
You would now have 12 postcards now you have to buy 3 of the single set to get to 15 cards
Answer:

Or

Step-by-step explanation:
We can represent this situation with an equation that shows that when b and p are added, then the total number of people will be 72
The number of people who bring supplies = b
The number of people, to whom supplies are provided = p
We get ;

Or

Answer:
1
Step-by-step explanation:
6x - 3 =3
6x =3 +3
6x =6
x=6 :6
x=1
Answer:
The answer is: -2.
Step-by-step explanation:
Note when x = -2 that the line passes through the point (-2, -2) so when x = -2 then y also = -2.
The answer is D. There is a positive correlation between the hours studied and grades earned.