Since you are assuming $R,W \
eq 0$, you can safely divide by them. Dividing $6R-2RW=0$ by $R$, you get $6-2W=0$ or $W=3$. Substitute that into the second equation to find $R$.
Since you are assuming $R,W \
eq 0$, you can safely divide by them. Dividing $6R-2RW=0$ by $R$, you get $6-2W=0$ or $W=3$. Substitute that into the second equation to find $R$.