3.5х+2.2х=4.56 3.7z-z=0.54

3.5х+2.2х=4.56 5.7х=4.56 х=4.56:5.7 х=0.8 3.7z-z=0.54 2.7z=0.54 z=0.54:2.7 z=0.2