6х=28-х 9х-26=30-5х 7-3х=6х-56 0.9х-7.4=-0.4х+4.3

1)6х=28-х
6х+х=28
7х=28
х=28:7
х=4
2)9х-26=30-5х
9х+5х=30+26
14х=56
х=56:14
х=4
3)7-3х=6х-56
-3х-6х=-56-7
-9х=-63
х=-63:(-9)
х=7
4)0.9х-7.4=-0.4х+4.3
0.9х+0.4х=4.3+7.4
1.3х=11.7
х=11.7:1.3
х=9