(12, 2 - 7ц 6/11) / (3ц 7/33)= (12ц 22/110 - 7ц 60/110) /(3ц 7/33) = 4ц 72/110 /(3ц 7/33) = 4ц 36/55 /(3ц 7/33) =(256/55) / (106/33)= (256/55) * (33/106) = (128*3) / (5*53) = 384/265 = 1ц 119/265
(5/9 + 7ц7/8 *2ц1/7) * 4ц3/3 = (5/9 + 63/8*15/7) *5 = (5/9 + (9*15)/(8*1)) *5 =(5/9 + 135/8) *5 = (40/72 + 1215/72) *5 = 1255/72 *5 = 1255*5/72= 6275 /72= 87ц 11/75