(3 1/2x-1/4)•8=3; =>>> (7/2х-1/4)•8=3; =>>> 7/2х• 8 -1/4• 8=3; =>>> 7/1х • 4- 1/1• 2=3; =>>> 28х-2=3; =>> 28х=3+2; =>> 28х=5; =>> х=5:28; =>> х= 5•1/28; =>> х=5/28; ____проверка (3 1/2• 5/28- 1/4)•8= (7/2• 5/28- 1/4)•8= (1/2• 5/4- 1/4)•8= (5/8- 1/4)•8= (5/8- 2/8)•8= 3/8• 8= 3/1=3.