Question

x+y=10, y+z=12,z+x=15 then x=?

Answer 1

hope this helps you....

Answer 2

 x+y=10;x+z=15;y+z=12 

Solution :

 {x,y,z} = {13/2,7/2,17/2} 

System of Linear Equations entered :

  [1] x + y = 10   [2] x + z = 15   [3] y + z = 12

Solve by Substitution :

// Solve equation [3] for the variable  z  
 

[3] z = -y + 12

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

  [2] x + (-? +12) = 15   [2] x = 3

// Solve equation [2] for the variable  x  
 

[2] x = ? + 3

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

  [1] (y +3) + y = 10   [1] 2y = 7

// Solve equation [1] for the variable  y  

  [1] 2y = 7    [1] y = 7/2 

// By now we know this much :

  x = y+3   y = 7/2   z = -y+12

// Use the  y  value to solve for  x  

  x = (7/2)+3 = 13/2 

// Use the  y  value to solve for  z  

  z = -(7/2)+12 = 17/2