Solution - Linear equations with two unknowns

System of Linear Equations entered :

   [1]    g - f = 0
   [2]    g + f = 12

Graphic Representation of the Equations :

    f + g = 0        f + g = 12  

  
 

Solve by Substitution :

// Solve equation [2] for the variable  f 
 

  [2]    f = -g + 12

// Plug this in for variable  f  in equation [1]

   [1]    g - (-g +12) = 0
   [1]    2g = 12

// Solve equation [1] for the variable  g 

   [1]    2g = 12 

   [1]    g = 6 

// By now we know this much :

    g = 6
    f = -g+12

// Use the  g  value to solve for  f 

    f = -(6)+12 = 6 

Solution :

 {g,f} = {6,6}