1) 2 2/5*(3 2/5 - 1 11/15) =4
3 2/5 - 1 11/15) = 17/5 - 26/15 = 17*3/5*3 - 26/15 = 51-26/15 =25/15=5/3= 1 2/3
2 2/5 * 1 2/3 = 12/5*5/3 = 12*5/5*3 = 60/15 = 4
3) 6 3\7*3 1\3: 1 2\7= 16 2/3
6 3/7*3 1/3 = 45/7*10/3 = 45*10/7*3 = 450/21 = 150/7 = 21 3/7
21 3/7 : 1 2/7 = 150/7 : 9/7 = 150/7 * 7/9 = 150*7/7*9 = 1050/63 = 50/3 = 16 2/3
4) (7 2\3- 5 4\5):2 4\5= 2/3
7 2/3 - 5 4/5 = 23/3 - 29/5 = 23*5/3*5 - 29*3/5*3 = 115/15 - 87/15 = 115-87/15 =28/15=1 13/15
1 13/15 : 2 4/5 = 28/15 : 14/5 = 28/15*5/14 = 28*5/15*14 = 140/210 = 2/3