The given function is x'yz' + x'yx + xy'z' + xy'z + xyz

 The mapping is shown below

       X'Y'  X'Y  XY  XY'

 Z'          1         1

 Z           1    1     

 After finding the two essential prime implicants m7 is still uncovered. The following are the two solutions.

 f = x'y + xy' + xz

 f = x'y + xy' + yz