a) 3 3/7 - 4 5/21 - 2 3/14=,,, b) 4 1/2 - ( 5 3/7 -1 3/14)=,,, c) 2 1/8 - (1 2/7 - 3 1/28)=,, a) 6:1 1/3=,, b) 1 1/2 :14=,,,c) 9:1 7/8=,,

3 3/7 - 4 5/21 - 2 3/14= 3 18/42 - 4 10/42 - 2 9/42 = -3 17/42 4 1/2 - ( 5 3/7 -1 3/14)= 4 7/14 - (5 6/14 - 1 3/14) = 4 7/14 - 4 3/14 = 4/14= 2/7 2 1/8 - (1 2/7 - 3 1/28) = 2 7/56 - (1 16/56 - 3 2/56)= 2 7/56 - (- 2 14/56)= 2 7/56 + 2 14/56 = 4 21/56= 4 3/8 6:1 1/3= 6 : 4/3= 6 * 3/4 = 9/2 = 4,5 1 1/2 :14= 3/2 * 1/14 = 3/28 9:1 7/8= 9 * 8/15 = 24/5 = 3 4/5