(1/12-1/13):(1/13-1/14):(1/14-1/15):(1/15-1/16)=

Расставим действия:1 5 2 6 3 7 4( 1/12 - 1/13 ) : ( 1/13 - 1/14 ) : ( 1/14 - 1/15 ) : ( 1/15 - 1/16 ) = 1/156 : 1/182 : 1/210 :: 1/240 = 91/78 : 1/210 : 1/240 = 245 : 1/240 = 58800.1) 1/12 - 1/13 = 13/156 - 12/156 = 1/156;2) 1/13 - 1/14 = 14/182 - 13/182 = 1/ 182;3) 1/14 - 1/15 = 15/210 - 14/210 = 1/210;4) 1/15 - 1/16 = 16/240 - 15/240 = 1/240;5) 1/156 : 1/182 = 1/156 * 182/1 = 182/156 = 91/78;6) 91/78 : 1/210 = 91/78 * 210/1 = 19110/78 = 245;7) 245 : 1/240 = 245/1 * 240/1 = 58800.