wx + wxy + w'yz + w'y'z + w'xyz'

  = (wx + wxy) + (w'yz + w'y'z') + w'xyz'

  = wx + w'z + w'xyz'

  = wx + w'(z + xyz')

  = wx + w'(z + xy)

  = wx + w'z + w'xy)

  =w'z +  x( w + w'y)

  =w'z +  x( w + y)

  =w'z +  wx + xy