25/28-18/35; 40/63-35/72; 22/21-21/22
1) 25/28 - 18/35 = 625/700 - 360/700 = 265/700 = 53/140 2) 40/63 - 35/72 = 2880/4536 - 2205/4536 = 675/4536 = 25/168 3)22/21 - 21/22 = 484/462 - 441/462 = 43/462
Спасибо огромное)))