Let a and o represent the numbers of apples and oranges sold the first week.
a + o = 108
Then the number sold the second week is
5a +3o = 452
Subtract 3 times the first equation from the second.
(5a +3o) -3(a +o) = (452) -3(108)
2a = 128 . . . . . . collect terms
a = 64 . . . . . . . . divide by 2
o = 108 - 64 = 44 . . . use the first equation to find o
64 apples and 44 oranges were sold the first week.
