Найдите значение выражение: 1) 4 2/5*15/77*7/20; 2) 5 2/5*40/81*15/16; 3) 12 6/7*2/25*7/18; 4) 3 9/10*8/13*4 1/6;

1) 4 2/5 * 15/77 * 7/20 = 22/5 * 15/77 * 7/20 = 11/1 * 3/11 * 1/10 = 3/10 = 0,3

2) 5 2/5 * 40/81 * 15/16 = 27/5 * 40/81 * 15/16 = 5/3 * 3/2 = 5/2 = 2 1/2 = 2,5

3) 12 6/7 * 2/25 * 7/18 = 90/7 * 2/25 * 7/18 = 5/1 * 2/25 * 1/5 = 2/25

4) 3 9/10 * 8/13 * 4 1/6 = 39/10 * 8/13 * 25/6 = 3/2 * 4/1 * 5/3 = 10