Ответ:

1) (5/7*7/3*5/6-1): (1-7/8*8/5*3/14)=(35/21*5/6-1):(1-56/40*3/14)=(175/126-1):(1-168/560)=(175/126-126/126): (560/560-168/560)=49/126:392/560=49*560/126*392=27440/49392= 1715/ 3087  

2) (127/15-15/4+22/5-487/60): (17/4-11/4) =( 508/60-225/60+264/60-487/60):6/4=60/60: 6/4= 4/6=2/3

3) (21/13*13/42+40/7:8/21):(65/8+7/2)= (273/546+40*21/7*8):(65/8+28/8)=

(273/546+840/56):37/8= (273/546+8190/546):37/8= 8463/546 =155/10:37/8=155*8/370=1240/370=124/37=3 13/37

4)  13/5:91/15+15/14-112/73*(40/7-81/16)=  

А)640/16-81/16=559/16

62608/1168=15652/292=3913 /73

195/455 + 3913/73= 14235 /33215+1780415/33215 =1794650/33215=54целых208/6643

Пошаговое объяснение:лллл