Вычислите 4/5*5/7 8/9*3/5 9/2*2/9 8/21*7/10 8/15*25/28 3/7*2 3*1/6 9*5/6 2/5*15 1/4*4 5*1/5 2 1/3*2 4*1 1/2 1 1/3*9 3/7*2

Чтобы вычислить значения, сократим числа в числителе и знаменателе, где необходимо представим обычную дробь в виде неправильной:

1) 4/5 * 5/7 = (4 * 5)/(5 * 7) = 4/7;

2) 8/9 * 3/5 = (8 * 3)/(3 * 3 * 5) = 8/15;

3) 9/2 * 2/9 = (9 * 2)/(2 * 9) = 1;

4) 8/21 * 7/10 = (2 * 4 * 7)/(7 * 3 * 2 * 5) = 4/15;

5) 8/15 * 25/28 = (4 * 2 * 5 * 5)/(5 * 3 * 4 * 7) = 10/21;

6) 3/7 * 2 = (3 * 2)/7 = 6/7;

7) 3 * 1/6 = 3/(3 * 2) = 1/2;

8) 9 * 5/6 = (3 * 3 * 5)/(3 * 2) = 15/2 = 7 1/2;

9) 2/5 * 15 = (2 * 5 * 3)/5 = 6;

10) 1/4 * 4 = 4/4 = 1;

11) 5 * 1/5 = 5/5 = 1;

12) 2 1/3 * 2 = 7/3 * 2 = 14/3 = 4 2/3;

13) 4 * 1 1/2 = 4 * 3/2 = (2 * 2 * 3)/2 = 6;

14) 1 1/3 * 9 = 4/3 * 9 = (4 * 3 * 3)/3 = 12;

15) 3/7 * 2 1/3 = 3/7 * 7/3 = 1;

16) 1 1/3 * 1 1/2 = 4/3 * 3/2 = (2 * 2 * 3)/(3 * 2) = 2.