I call the apple pies is a and hamburger is b so:
4a + 3b = 47
6a + 5b = 75
a = (47 - 3b)/4
6 ((47- 3b) /4) + 5b = 75
6(47- 3b) +20b = 300
282 - 18b + 20b = 300
2b = 18
b = 9
We have 4a + 3b = 47 and we have the value of b so:
4a + 3.9 = 47
4a = 20
a = 5
The apple pie is 5$ and the hamburger is 9$