9/25 * 2 1/7- (-1 5/9)
9/25*2 1/7=9/25*15/7=27/35
27/35-(-1 5/9)=27/35+14/9=243/315+490/315=369/225=733/225=3 58/225
4 3/7 : 1/7 - 1 5/6 * 3
4 3/7 : 1/7=31/7*7/1=31
1 5/6*3=11/6*3=11/2=5.5
31-5.5=25.5
- 2/5 * 0,16 - 2/5 * 4,84
-2/5(0.16+4.84)=-2/5*5=-2