Вычислите: 1) (-3/14-8/21) : 20/21 2) 3/8: (-5/8) - (-2 1/4) : (-1 4/11)

Первый:

1) - 3/14 - 8/21 = - 18/84 - 32/84 = - 50/84 = - 25/42;

2) - 25/42 : 20/21 = - 25/42 * 21/20 = - 5/2 * 1/4 = - 5/8.

Ответ: - 5/8.

Второй:

1) 3/8 : ( - 5/8) = 3/8 * ( - 8/5) = 3/1 * ( - 1/5) = - 3/5;

2) - 2 1/4 : ( - 1 4/11) = - 9/4 : ( - 15/11) = - 9/4 * ( - 11/15) = - 3/4 * ( - 11/5) = 33/20 = 1 13/20;

3) - 3/5 - 1 13/20 = - 12/20 - 1 13/20 = - 1 25/20 = - 2 1/4.

Ответ: - 2 1/4.