(15/21+8/12)*14/10-3/6÷4/6
(15/21+8/12)*14/10-3/6:4/6=(60/84+56/84)*14/10-3/4=29/21*14/10-3/4=29/15-3/4=71/60
1) 15/21 + 8/12=60/84+56/84=116/84=1 32/84= 1 16/42= 1 8/21 2) 1 8/21*14/10= 29/21 * 14/10=29/3 * 2/10= 58/30= 1 28/30= 1 14/15 3) 3/6 : 4/6= 3/6*6/4=3/1*1/4=3/4 4) 1 14/15-3/4=29/15-3/4=116/60-45/60=71/60=1 11/60 ОТВЕТ= 1 11/60