(72-64/(40-8х))*4=272
72-64/(40-8х)=272/4
72-64/(40-8х)=68
64/(40-8х)=72-68
64/(40-8х)=4
40-8х=64/4
40-8х=16
8х=40-16
8х=24
х=24/8
х=3
72 - 64:(40 - 8x) = 272/4
72 - 64:(40 - 8x) = 68
64:(40 - 8x) = 4
40 - 8x = 16
8x = 24
x = 3
ответ: 3.
(72-64/(40-8х))*4=272
72-64/(40-8х)=272/4
72-64/(40-8х)=68
64/(40-8х)=72-68
64/(40-8х)=4
40-8х=64/4
40-8х=16
8х=40-16
8х=24
х=24/8
х=3