Verified Answer :

Solutions  

In Matrix we use initially based on systems of linear equations.The matrix method is similar to the method of Elimination as but is a lot cleaner than the elimination method.Solving systems of equations by Matrix Method involves expressing the system of equations in form of a matrix and then reducing that matrix into what is known as Row Echelon Form. 

Calculations 

⇒ Rewrite the linear equations above as a matrix 

\(\left[\begin{array}{ccc}3&5&42\\6&5&54\\\end{array}\right]\) 

⇒  Apply to Row₂ : Row₂ - 2 Row₁ 

\(\left[\begin{array}{ccc}3&5&42\\0&-5&-30\\\end{array}\right]\) 

⇒ Simplify rows

\(\left[\begin{array}{ccc}3&5&42\\0&1&6\\\end{array}\right]\) 

Note: The matrix is now in echelon form.
The steps below are for back substitution. 

⇒ Apply to Row₁ : Row₁ - 5 Row₂ 

\(\left[\begin{array}{ccc}3&0&12\\0&1&6\\\end{array}\right]\) 

⇒ Simplify rows 

\(\left[\begin{array}{ccc}1&0&4\\0&1&6\\\end{array}\right]\) 

⇒ Therefore, 

\(x=4 y = 6\)