Question

You decide you want to become a photographer and you want to see how much money you can make doing so. As you look into current prices, you decide you can offer two deals: 5 small photos and 8 large photos for $92 or 10 small photos and 3 large photos for $67. How much are you charging for a single small photo and a single large photo in these deals?

Answer 1

For the first one: 5 small photos and 8 large for 92 dollars
--> 5s + 8L = 92
For the second one: 10 small and 3 large for 67
--> 10s + 3L = 67

Then, use the two equations.
(5s +8L) -2 = 92(-2)
10s + 3L = 67

-10s - 16L = -184
10s + 3L = 67
-----------------
0 - 13L = -117

--> -13L = -117 --> L = 9 $'s

So you know that each large photo costs 9 dollars. Now what do you have to do to find the price of each small photo?