1. 3a³b²(x-2y)-9a²b³(x+2y)
2. 3x(x-2)-2(2-x)
3x(x-2)-2(2-x)
=3x(x-2)+2(x-2)
=(x-2)(3x+2)
3a³b²(x-2y)-9a²b³(x+2y)
=(x-2y)(3a³b²+9a²b³)
=3a²b²(x-2y)(a+3b)