Solve the equation x+y+z =6 2x-y+3z =9 3x+3y-5z = -6

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

// Plug this in for variable  z  in equation [3]

// Solve equation [2] for the variable  x 
 

// Plug this in for variable  x  in equation [3]

// Solve equation [3] for the variable  y 

// By now we know this much :

// Use the  y  value to solve for  x 

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

the answer to your question is minor arc.