(5 5/7х3/8-5 1/4:7):3+3 3/28-1/2=по действиям ответ 1/14 

(5 5/7 * 3/8 - 5 1/4 : 7) : 3 + 3 3/28 - 1/2 = 3 целых 1/141) 5 5/7 * 3/8 = 40/7 * 3/8 = (5*3)/(7*1) = 15/7 = 2 1/72) 5 1/4 : 7 = 21/4 : 7 = 21/4 * 1/7 = (3*1)/(4*1) = 3/43) 2 1/7 - 3/4 = 2 4/28 - 21/28 = 1 32/28 - 21/28 = 1 11/28 = 39/284) 39/28 : 3 = 39/28 * 1/3 = (13*1)/(28*1) = 13/285) 13/28 + 3 3/28 = 3 16/28 = 3 4/76) 3 4/7 - 1/2 = 3 8/14 - 7/14 = 3 1/14