0.4*0.3х=7.8
0.12х=7.8
х=65
1) 1/3 < x < 1/2
8/24 < x < 12/24
Таким образом, x∈ 9/24; 10/24; 11/24
2) a) 4/9 < x < 5/9 b) 1/8 < x < 1/7
12/27 < x < 15/27 7/56 < x < 8/56
x∈ 13/27; 14/27 21/168 < x < 24/168
x∈ 22/168; 23/168
26,22-3 2/5=26,22-3,4=22,82
<span>ответ:2,7*0,726=1,9602
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