(8,3-x)*4,7=5,64 x+0.23=3/4+0.5 2.136: (1.9-x)=7 3/25

(8,3-x)*4,7=5,64
8.3-х=5.64:4.7
8.3-х=1.2
-х=1.2-8.3
-х=-7.1
х=7.1

x+0.23=3/4+0.5
х=0.75+0.5-0.23
х=1.02

2.136:(1.9-x)=7 3/25
1.9-х=2.136:7.12
1.9-х=0.3
-х=0.3-1.9
-х=-1.6
х=1.6