2/5 < 4/5
12/17 > 7/17
17/13 > 15/13
1)<span>x = 743 - 87 x
88х=743
х=743/88
х=8целых39/88.
2)</span><span>743 - 87 x = 720 : 8
</span><span>743 - 87 x = 90
-87х=-653
х=7целых44/87.
3)</span><span>x =720 : 8
х=90.</span>
725t-123t=912+292 602t=1204 t=1204/602 t=2