Вычислите 1) 5 5/7*9/20 2) 2 1/4:1 1/8 3) - 5 1/2 * (-8 1/11) 4) - 3 5/9*4 7/8 5) 1,2+3/7 6) - 0,4+5/6

Вычислим значения выражений:

1) 5 5/7 * 9/20 = (5 * 7 + 5) / 7 * 9/20 = (35 + 5) / 7 * 9/20 = 40/7 * 9/20 = (20 * 2 * 9) / (7 * 20) = (2 * 9) / 7 = 18/7 = 2 4/7;

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

3) - 5 1/2 * (-8 1/11) = (5 * 2 + 1) / 2 * (8 * 11 + 1) / 11 = 11/2 * 89/11 = 89/2 = 44 1/2;

4) - 3 5/9 * 4 7/8 = - (3 * 9 + 5) / 9 * (4 * 8 + 7) / 8 = - 32/9 * 39/8 = - (8 * 4 * 3 * 13) / (3 * 3 * 8) = - (4 * 13) / 3 = - 52/3 = - 17 1/3;

5) 1,2 + 3/7 = 1 + 2/10 + 3/7 = 1 + 14/70 + 30/70 = 1 44/70 = 1 22/35;

6) - 0,4 + 5/6 = - 4/10 + 5/6 = - 24/60 + 50/60 = 26/60 = 13/30.