Question

Amelie has three dogs, Max, Jasmine, And Springer. She buys a bag of dog food that contains a special mix.

Answer 1

1/3 + 1/4 + x = 1 bag
4/12 + 3/12 + x = 1
7/12 + x = 1
x = 1 - 7/12
x = 12/12 - 7/12
x = 5/12

Answer 2

1/4 is the same as 3/12 and 1/3 is the same as 4/12. The full bag of dog food can be represented by the fraction 12/12. So if we subtract 3/12 and 4/12 from 12/12 we will be left with the rest of the dog food(which springer get fed), which is 5/12