4 3/4 would be changed to 19/4 because 4(4)+3 = 19 and then we keep the the same denominator (which is 4)
19/4 - 1/3 = 4 5/12
Because, 4 + (3/4 - 1/3)
3/4 - 1/3 = _____
9/12 - 4/12 = 5/12
Now, attach the "4" from 4 3/4 (the. one at the beginning )
and that's how you get the result of 4 5/12
☺