Найти значение выражения -3/7 * 7/9 , 2 1/7 *3 1/9 , 3/7 :9/7 , 1 1/8 : 3/4 , 3 3/5 : 2 7/10 , 5/8 * 4/5 , 4 2/3 * 1

1) -3/7 * 7/9 = -(3 * 7)/(7 * 9) = -3/9 = -1/3;

2) 2 1/7 * 3 1/9 = (2 * 7 + 1)/7 * (3 * 9 + 1)/9 = (14 + 1)/7 * (27 + 1)/9 = 15/7 * 28/9 = (15 * 28)/(7 * 9) = 20/3;

3) 3/7 : 9/7 = 3/7 * 7/9 = 1/3;

4) 1 1/8 : 3/4 = 9/8 * 4/3 = (9 * 4)/(8 * 3) = 3/2;

5) 3 3/5 : 2 7/10 = (3 * 5 + 3)/5 : (2 * 10 + 7)/10 = 18/5 * 10/27 = 4/3;

6) 5/8 * 4/5 = 4/8 = 1/2;

7) 4 2/3 * 1 2/7 = 14/3 * 9/7 = 6;

8) 3/4 : 9/8 = 3/4 * 8/9 = 2/3;

9) 1 5/7 : 1 1/7 = 12/7 * 7/8 = 3/2;

10) 3 1/5 : 2 2/15 = 16/5 : 32/15 = (16 * 15)/(5 * 32) = 3/2.