11 1/4*1/9-4 7/12*4/11
(45/36)-(55*4/12*11)=(45/36)-(220/132) Сокращаем 45 и 36 на 9; 220 и 132 на 4 (5/4)-(55/33) Сокращаем 55 и 33 на 11 (5/4)-(5/3) =(5*3-5*4)/12=(15-20)/12=-5/12
11 1/4*1/9-4 7/12*4/11= 11.1/4*1/9=45/4*1/9=5/4=1.1/4 4.7/12*4/11=55/12*4/11=5/3=1.2/3 1.1/4-1.2/3=(1-1)-(3/12-8/12)=-5/12