Question 1019869
Commonly known methods to solve a linear system of equations are Substitution, Elimination, and Row-reduction, or use of matrices.



Try to simplify your second equation.
{{{81y+27=162x}}}
{{{162x-81y=27}}}
{{{18x-9y=3}}}
{{{6x-3y=1}}}-------------identical to the first equation of your list.


You do not really have a system of equations any more; but instead just one single linear equation in two variables.