Write as a system y= 2 x + 2.4x - 2y = 4 
{y = 4 
{2x + 2.4x - 2y = 4 
  Substitute the value of y into the equation 
 2x + 2.4x - 2 x 4 = 4 
  Solve the equation
  x= 30/ 11 
  A possible solution is 
  (x, y) = (30/11, 4) 
  Check the solution 
  4 = 2 x 30/11+ 2.4 x 30/11 - 2 x 4 = 4 
  Simplify the expression 
  4 = 4 = 4 
  The ordered pair is a solution 
   (x, y) = ( 30/11, 4)