(5,4 - 2 1/3) : 7 2/3 = 0,4
1) 5,4 - 2 1/3 = 5 2/5 - 2 1/3 = 5 6/15 - 2 5/15 = 3 целых 1/15
2) 3 1/15 : 7 2/3 = 46/15 : 23/3 = 46/15 * 3/23 = (2*1)/(5*1) = 2/5 = 0,4
Пояснения:
0,4 = 4/10 = 2/5
2/5 = 6/15 - доп.множ. 3
1/3 = 5/15 - доп.множ. 5
3 целых 1/15 = (3*15+1)/15 = 46/15
7 целых 2/3 = (7*3+2)/3 = 23/3
2/5 = 4/10 = 0,4