Question

[Rinko Hanakawa]

bài 1: thực hiện các phép tính sau:

a) -2x³y.(2x² - 3y + 5yz)                               d) 2/3 x²y.( 3xy - x² + y)

b) ( x - 2y) (x²y² - xy + 2y )                           e) ( x-y)( x² + xy+ y² )

c) 2/5xy( x²y - 5x + 10y)                                f) (1/2xy - 1) .( x³ - 2x - 6)

Answer 1

[Bexiu]

Bài làm

c)25xy(x2y−5x+10y)25xy(x2y−5x+10y)

=25x3y2−x2y+4xy2=25x3y2−x2y+4xy2

d)23x2y(3xy−x2+y)23x2y(3xy−x2+y)

=2x3y2−23x4x+23x2y2=2x3y2−23x4x+23x2y2

e)(12xy−1)(x3−2x−6)(12xy−1)(x3−2x−6)

=12x4y−x2y−3xy−x3+2x+6=12x4y−x2y−3xy−x3+2x+6

=12x4y−x3−x2y+2x+6=12x4y−x3−x2y+2x+6