b) ( x^2y^2 - 1/2 xy+ 2) ( x-2y)

b) x2y2−12xy+2x−2y

=x2y2  .  x−12xy  .  x+2  .  x−x2y2  .  2y+12xy  .  2y−2  .  2y

=x3y2−12x2y +2x−2x2y3+xy2−4y