Jawabanmu

2014-08-23T16:11:50+07:00
520xy + 879yx - 5567xy + 444xxy
=1399xy - 5567xy + 444xxy
= xy(-4168 + 444x)
= -4xy(1042 - 111x)

Note: xy dan yx sama saja, ingat prinsip ab = ba

Semoga membantu