y = x - 1
x + 4y = 16
Im having troubles. Can some 1 explain in complete explanations and all expressions.

Respuesta :

{x,y} = {4, -3}

Substitution :

// Solve equation [2] for the variable  x  

 [2]    x = 4y + 16

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

  [1]    (4y+16) + y = 1

  [1]    5y = -15

// Solve equation [1] for the variable  y  

  [1]    5y = - 15

  [1]    y = - 3

// By now we know this much :

   x = 4y+16

   y = -3

// Use the  y  value to solve for  x  

   x = 4(-3)+16 = 4