Ответ:\(2{,}5x-x+3{,}8x+0{,}7x=0{,}54\); \(6x=0{,}54\); \(x=0{,}09\).\(0{,}1x+0{,}5=0{,}4x\); \(0{,}5=0{,}3x\); \(x=\frac53=1\frac23\).