1) 1ц1/2* 3ц2/5=(2*1+1)/2 * (3*5+2)/5=3/2* 15/5= (3*15)/(2*5)=45/10=4ц5/10;
2)4ц1/7* 7/16=(7*4+1)/7 *7/16=(29*7)/(7*16)=203/112;
Деление 1)2/27:1ц1/3=2/27: (3*1+1)/3=2/27: 4/3=2/27* 3/4=(2*3)/(27*4)=6/108; 2)3ц1/18: 2ц4/9=(18*3+1)/18: (9*2+4)/9=55/18: 22/9= 55/18* 9/22= (55*9)/(18*22)= 495/396=1ц99/396;