Bài 1 . ( 20x4y - 25x2y2 - 3x2 y) : 5x2y
= 5x2y.( 4x2 - 5y - \(\dfrac{3}{5}\)) : 5x2y
= 4x2 - 5y - \(\dfrac{3}{5}\)
Bài 2 . a) ( -2x5 + 3x2 - 4x3) : 2x2
= 2x2.( -x3 + \(\dfrac{3}{2}\) - 2x ) : 2x2
= - x3 - 2x + \(\dfrac{3}{2}\)
b) ( x3 - 2x2y + 3xy2) : ( \(\dfrac{1}{2}x\))
= \(\dfrac{1}{2}x\).( 2x2 - 4xy + 6y2) : ( \(\dfrac{1}{2}x\))
= 2x2 - 4xy + 6y2
c) ( 3x2y2 + 6x2y3 - 12xy ) : 3xy
= 3xy.( xy + 2xy2 - 4 ) : 3xy
= xy + 2xy2 - 4