49.
a. 2/7 : 3/5 = 2/7 × 5/3 = 10/21
b. -5/4 : 9/-11 = -5/4 × -11/9 = 55/36
50.
a. -7/6 : 3/4 = -7/6 × 4/3 = -28/18 = -14/9
b. 3/8 : -3/4 = 3/8 × -4/3 = -1/2 ( car 3/3 = 1)
c. -5/9 : -8/3 = -5/9 × -3/8= -5/24 ( car 3/9 = 1/3)