Solve the system by the substitution method. If there is exactly one solution, write as an ordered pair. If not, choose one of the other options.

{6x+3y=124x+y=6\displaystyle {\left\lbrace\begin{array}{ccccc} {6}{x}&+&{3}{y}&=&{12}\\{4}{x}&+&{y}&=&{6}\end{array}\right.}