1.
1) 4 2/7*1 3/4 = 30/7*7/4 = 15/2 = 7,5
2) 7,5-3,36 = 4,14
3) 0,8+1,5 = 2,3
4) 4,14/2,3 = 1,8
2. 70:5/7 = 70:5*7 = 14*7 = 98
3. 100%-29% = 71%
142:71% = 142:71*100 = 2*100 = 200
4. y-5/9y = 3 3/5
4/9y = 18/5
y = 18/5*9/4
y = 81/10 = 8,1
5. 1-9/16 = 7/16 = 105/240
1-8/15 = 7/15 = 112/240
105/240 < 112/240
У младшей осталось больше.