Выполните действия: 1) 5/6×9/15-5/12×4/15; 2) 7/18×9/14+1/3×6/7; 3) 9/20×2/3+5/14×7/25; 4) 3 3/4×2/5-3 6/25×5/27; 5) 2 2/5×5/6-3/4×1 2/3; 6) 1 17/18×14/9+14/25×5/7.

5/6*9/15-5/12*4/15= 3/6 - 1/9 =7/18

7/18*9/14 + 1/3*6/7 = 1/4+ 2/7 =15/28

9/20*2/3 + 5/14*7/25 = 3/10+1/10 = 4/10 = 2/5

3 3/4 *2/5 - 3 6/25*5/27 = 15/4 *2/5 - 81/25 * 5/27 = 3/2 - 3/5 = 9/10

2 2/5*5/6 - 3/4*1 2/3 = 12/5*5/6 - 3/4*5/3 = 2 - 5/4 = 3/4

1 17/18*14/9 + 14/25*5/7 = 35/18*14/9 + 14/25*5/7 =245/81 + 2/5 = 

= 1225/405 + 162/405 = 1387/405