Jawapan

2016-03-13T09:38:56+08:00
(x-1y5)2 (2xy-2)5
=(2x-2y10) (10xy-10)
=(-2y10+10) (10xy-2x)
=(-2y20) (8xy)
=(20) (8xy-2y)
=160xy-40y
=120xy