5x+x +7=16解:6x +7 =166x =16-76x =9x =9÷6x =3/2检验将x =3/2代入原式可得5×3/2+3/2+7=18/2+7=9+7=16
6x=9x=1.55x+x+7=6x+7=6×1.5+7=9+7=16