2) (1-4/3) / (1/3-1/4)

Step 1: Simplify the expressions inside the parentheses:
1 - 4/3 = 3/3 - 4/3 = (3-4)/3 = -1/3
1/3 - 1/4 = 4/12 - 3/12 = (4-3)/12 = 1/12

Step 2: Divide the simplified expressions:
(-1/3) / (1/12) = (-1/3) * (12/1) = -12/3 = -4

Therefore, the result of (1-4/3) / (1/3-1/4) is -4.

4) (5/7 - 2/3) / (4/9 - 5/12)

Step 1: Simplify the expressions inside the parentheses:
5/7 - 2/3 = 15/21 - 14/21 = (15-14)/21 = 1/21
4/9 - 5/12 = 16/36 - 15/36 = (16-15)/36 = 1/36

Step 2: Divide the simplified expressions:
(1/21) / (1/36) = (1/21) * (36/1) = 36/21 = 12/7

Therefore, the result of (5/7 - 2/3) / (4/9 - 5/12) is 12/7.