Solve the system of equations using matrices. Use Gaussian elimination with back-substitution
or Gauss-Jordan elimination. Express the solution set as \{(w,x,y,z)\}.
3w+4x+3y- 3z = 38
w+x-y+z= 2
3w+x-2y-2z = 11
-w+2x+y-3z = 6
The solution set is \{\boxed{\hspace{0.5cm}},\boxed{\hspace{0.5cm}},\boxed{\hspace{0.5cm}},\boxed{\hspace{0.5cm}}\}. (Simplify your answers.)