Solution - Linear equations with two unknowns

System of Linear Equations entered :

   [1]    3x - y = 3
   [2]    3x + 2y = 12

Graphic Representation of the Equations :

    y + 3x = 3        2y + 3x = 12  

  
 

Solve by Substitution :

// Solve equation [1] for the variable  y 
 

  [1]    y = 3x - 3

// Plug this in for variable  y  in equation [2]

   [2]    3x + 2•(3x-3) = 12
   [2]    9x = 18

// Solve equation [2] for the variable  x 

   [2]    9x = 18 

   [2]    x = 2 

// By now we know this much :

    x = 2
    y = 3x-3

// Use the  x  value to solve for  y 

    y = 3(2)-3 = 3 

Solution :

 {x,y} = {2,3}