Question

By using cramers rule x-4+3z=5; 4x+2y-z =0
x+3y+z=5.​

Answer 1

Answer:

// Solve equation [3] for the variable  z  

 

 [3]    z = -x - 3y + 5

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

  [1]    x + 3•(-x -3?+5) = 9

  [1]    -2x = -6

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

  [2]    4x - (-x -3y+5) + 2y = 0

  [2]    5x + 5y = 5

// Solve equation [2] for the variable  y  

 

 [2]    5y = -5x + 5

 [2]    y = -x + 1

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

  [1]    -2x = -6

  [1]    7x = 3

// Solve equation [1] for the variable  x  

  [1]    7x = 3  

  [1]    x = 3/7  

// By now we know this much :

   x = 3/7

   z = -x-3y+5

   y = -x+1

// Use the  x  value to solve for  y  

   y = -(3/7)+1 = 4/7  

// Use the  x  and  y  values to solve for  z  

 z = -(3/7)-3(4/7)+5 = 20/7  

Solution :

{x,z,y} = {3/7,20/7,4/7}