Пж момогит мучуюсь и не могу

1) (3/4 + 1/20) *1/2 = (15/20 + 1/20) * 1/2 = 16/20 * 1/2 = 8/20 = 2/5 2) (7 3/5 - 2 4/15) * 9/32 = (38/5 - 34/15) * 9/32 = (114/15 - 34/15) * 9/32 =          80/15 * 9/32 = 3/2 = 1 1/2 3) (5 1/2 + 2 3/5) * 5/9 = (11/2 + 13/5) * 5/9 = (55/10 + 26/10) * 5/9 = 81/10 * 5/9     =  9/2 = 4 1/2