Kevin order 2 hamburgers and 3 sodas for $4.13 at the Burger Sport. Alana order 4 cheeseburgers and 6 sodas. Cheeseburger costs 15 cents more than hamburger. Ho

Question

Kevin order 2 hamburgers and 3 sodas for $4.13 at the Burger Sport. Alana order 4 cheeseburgers and 6 sodas. Cheeseburger costs 15 cents more than hamburger. How many dollars does Alana's order cost?

Answer 1

Hi Serina-

 

We can break this down and try to simplify it. Let hamburgers=H, sodas=S, and cheeseburgers=C. Now let's write down everything we know.

 

Kevin's order: 2H+3S=4.13

Alana's order: 4C+6S

Cheeseburgers cost more than hamburgers: C=H+.15

We can get ride of the C in Alana's order by substitution. Alana's order now reads: 4(H+.15)+6S. Let's simplify this to the following: 4H+0.6+6S. This looks an awful lot like Kevin's order, but twice as much. Let's try to make it look like Kevin's by rewriting it.

Alana's order: 0.6+2(2H+3S). We know 2H+3S=4.13 from Kevin's order. We can plug that in to achieve the following:

Alana's order: 0.6+2(4.13)=0.6+8.26=8.86. Does that make sense?