Answer: $7.20
Step-by-step explanation: I find that proportions are the easiest to use when it comes to these types of problems. First, set up your proportion, it doesn't matter what is on the top or bottom as long as both sides have the same unit on top or bottom.
I started with the two numbers it gives us to base our answer off of. In this case, it is 5 pounds of apples costs 12$:
[tex]\frac{5 pounds}{12dollars}[/tex]
Next, set up the second half of the proportion, but add 'x' in place of what we are solving for, in this case the dollars.
[tex]\frac{5 pounds}{12dollars} = \frac{3 pounds}{x}[/tex]
Cross multiply here, or butterfly multiplication, or whatever it is called. Either way, multiply diagnolly twice, so in this case multiply 5 by x and 12 by 3. Write your numbers on each side of the equals sign.
[tex]5x = 36[/tex]
Solve for x. Do this by dividing 36 by 5.
[tex]x = 7.2 dollars[/tex]
That's your answer. Hopes this helps solve proportions in the future!
