5,8х+7,04х=3,21
12,84х=3,21
х=3,21/12,84
х=0,25
0,32у-7,29=5,67
0,32у=12,96
у=12,96/0,32
у=40,5
(2.61-4х):0.03+4.6=90
(2.61-4х):0.03=90-4.6
(2.61-4х):0.03=85.4
2.61-4х=85.4*0.03
2.61-4х=2.562
-4х=2.562-2.61
-4х=-0.048
х=-0.048:(-4)
х=0.012.
8,36-5,36:(0,2x+0,47 x)=7,56
8,36-5,36:0,67х=7,56
5,36/0,67х=8,36-7,56
5,36/0,67х= 0,8
0,67х=5,36/0,8
0,67х= 6,7
х= 6,7/0,67
х= 10