Solution - Linear equations with two unknowns

System of Linear Equations entered :

   [1]    a + b = 17
   [2]    a - b = 5

Graphic Representation of the Equations :

    b + a = 17        b + a = 5  

  
 

Solve by Substitution :

// Solve equation [2] for the variable  a 
 

  [2]    a = b + 5

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

   [1]    (b +5) + b = 17
   [1]    2b = 12

// Solve equation [1] for the variable  b 

   [1]    2b = 12 

   [1]    b = 6 

// By now we know this much :

    a = b+5
    b = 6

// Use the  b  value to solve for  a 

    a = (6)+5 = 11 

Solution :

 {a,b} = {11,6}