1)4/5 + 2 1/7 = 4/5 + 15/7 =(4 × 7 + 15 × 5)/35 = 28/35 + 75/35 = 103/35 = 2 33/35
2)2 33/35 + 1 1/5 = 103/35 + 6/5 =(103 × 1 + 6 × 7)/35 = 103/35 + 42/35 = 145/35 = 29/7 = 4 1/7
3)4 1/7 + 3 6/7 = 29/7 + 27/7 = 56/7 = 8
ответ 8
2,04*3,52-3,52*1,04+0,48=4
2,04*3,52=7,1808
3,52*1,04= 3,6608
7,1808-3,6608=3,52
3,52+0,48=4