1/8u-2=5/8u+1
1*(8u+1)=5*(8u-2)
8u+1=40u-10
8u-40u=-10-1
-32u=-9
u=9/32
<span><span><span><span>
а
</span><span>
10
</span><span>
100
</span><span>
1000
</span><span>
10000
</span><span>
100000
</span></span><span><span>
а*10
</span><span>
100
</span><span>
1000
</span><span>
10000
</span><span>
100000
</span><span>
1000000
</span></span><span><span>
а:10
</span><span><span> 1</span></span><span>
10
</span><span>
100
</span><span>
1000
</span><span>
10000
</span></span><span><span>
а+10
</span><span>
20
</span><span>
110
</span><span>
1010
</span><span>
10010
</span><span>
100010
</span></span><span><span>
а-10
</span><span>
0
</span><span>
90
</span><span>
990
</span><span>
9990
</span><span>
99990
</span></span></span></span>
Если округлить, то 40,53. Подробнее на фотке
1) 24х*100=9600
2400х=9600
х = 9600/2400
х=4
2) 25*4+х*4=360
100+4х=360
4х=360-100
4х=260
х=260/4
х=65