y_(K)=(y_{E}+[red]3[/red]*y_(F))/(1+[red]3[/red])
z_(K)=(x_{E}+[red]3[/red]*z_(F))/(1+[red]3[/red])
0=(-1+[red]3[/red]*x_(F))/1+[red]3[/red]) ⇒ x_(F)=1/3
0=(2+[red]3[/red]*y_(F))/(1+[red]3[/red]) ⇒ y_(F)=-2/3
2=(4+[red]3[/red]*z_(F))/(1+[red]3[/red]) ⇒ z_(F)=(8-4)/3=4/3