2 3/4-1 7/12=. 7 1/4-4 5/8=

1) 23/4-17/12=23/4×3-17/12=69/12-17/12=52/12=4 4/12=4 1/3
2) 71/4-4 5/8=71/4×2-4 5/8=142/8-37/8=105/8=13 1/8