ОЧЕНЬ СРОЧНО! ! !  Выполните действия: 1 5/7:1 1/7; 3 1/5:2 2/15; 5 2/3:1/3-1 7/12*6

Спасибо.

1 5/7 : 1 1/7 = 12/7 : 8/7 = 12/7 * 7/8 = 12/8 = 1 4/8 = 1 1/23 1/5 : 2 2/15 = 16/5 : 32/15 = 16/5 * 15/32 = (1*3)/(1*2) = 3/2 = 1 1/25 2/3 : 1/3 - 1 7/12 * 6 = 7 1/21) 5 2/3 : 1/3 = 17/3 * 3/1 = 17 2) 1 7/12 * 6 = 19/12 * 6 = 19/2 = 9 1/23) 17 - 9 1/2 = 16 2/2 - 9 1/2 = 7 1/2