\"\"

\

Guassian elimination method :

\

System of equations are

\

  \"\"

\

Solve the equation \"\" for \"\".

\

\"\"

\

Substitute \"\" in equation \"\".

\

\"\"

\

\"\".

\

\"\"

\

\"\" .

\

Substitute \"\" in \"\".

\

\"\".

\

\"\".

\

\"\" and  \"\".

\

\"\"

\

\"\".