Вычтслите произвкдение 13/10*100/39; 7/8*4/35*10/9; 42/56*16/5*15/36; 6/7*5/6; 13/15*45/26; 5/7*7/13*13/18; 101/102*102/103*103/104; 6/7*7/6.

Находим решение математическим выражения, выполняя умножение дробных чисел:

1) 13/10 х 100/39 = (13 х 100) / (10 х 39) = (1 х 10) / (1 х 3) = 10/3 = 3 1/3;

2) 7/8 х 4/35 х 10/9 = 1/9;

(7 х 4) / (8 х 35) = (1 х 1) / (2 х 5) = 1/10;

1/10 х 10/9 = (1 х 10) / (10 х 9) = (1 х 1) / (1 х 9) = 1/9

3) 42/56 х 16/5 х 15/36 = 1;

42/56 х 16/5 = (42 х 16) / (56 х 5) = (6 х 2) / (1 х 5) = 12/5;

12/5 х 15/36 = (12 х 15) / (5 х 36) = (1 х 3) / (1 х 3) = 3/3 = 1;

4) 6/7 х 5/6 = (6 х 5) / (7 х 6) = (1 х 5) / (7 х 1) = 5/7;

5) 13/15 х 45/26 = (13 х 45) / (15 х 26) = (1 х 3) / (1 х 2) = 3/2 = 1 1/2 или 1,5;

6) 5/7 х 7/13 х 13/18 = 5/18;

5/7 х 7/13 = (5 х 7) / (7 х 13) = (5 х 1) / (1 х 13) = 5/13;

5/13 х 13/18 = (5 х 13) / (13 х 18) = (5 х 1) / (1 х 18) = 5/18;

7) 101/102 х 102/103 х 103/104 = 101/104;

101/102 х 102/103 = (101 х 102) / (102 х 103) = (101 х 1) / (1 х 103) = 101/103;

101/103 х 103/104 = (101 х 103) / (103 х 104) = (101 х 1) / (1 х 104) = 101/104;

8) 6/7 х 7/6 = (6 х 7) / (7 х 6) = (1 х 1) / (1 х 1) = 1/1 = 1.