1) 2 13/48 - (-2 5/12) = 109/48 + 29/12 = 109/48 + 116/48 = 225/48

2) 225/48 : (-3 3/4) = 225/48 : (-15/4) = 225/48 * (- 4/15) = - 15/12

3) 9 3/4 : (-13) = 39/4 * (-1/13) = - 3/4

4) -15/12 + (-3/4) = -15/12 - 9/12 = -24/12 = - 2