Question

x+3y+4z=4 and 4x+ 2y+3z=2 solve eq

Answer 1

2x+4y-3z=-7;3x+y+4z=-12;x+3y+4z=4 

Solution :

 {x,y,z} = {-6,2,1} 

System of Linear Equations entered :

  [1] 2x + 4y - 3z = -7   [2] 3x + y + 4z = -12   [3] x + 3y + 4z = 4

Solve by Substitution :

// Solve equation [3] for the variable  x  
 

[3] x = -3y - 4z + 4

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

  [1] 2•(-3y-4z+4) + 4y - 3z = -7   [1] - 2y - 11z = -15

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

  [2] 3•(-3y-4z+4) + y + 4z = -12   [2] - 8y - 8z = -24

// Solve equation [2] for the variable  z  
 

[2] 8z = -8y + 24 [2] z = -y + 3

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

  [1] - 2y - 11•(-y +3) = -15   [1] 9y = 18

// Solve equation [1] for the variable  y  

  [1] 9y = 18    [1] y = 2 

// By now we know this much :

  x = -3y-4z+4   y = 2   z = -y+3

// Use the  y  value to solve for  z  

  z = -(2)+3 = 1 

// Use the  y  and  z  values to solve for  x  
  x = -3(2)-4(1)+4 = -6 

Solution :

 {x,y,z} = {-6,2,1} 

Answer 2

endj$'#:8654676fidhdoiwbxhwjvzdhuz high go