Nhanh nha các bạn :)))

Đáp án:

 

Giải thích các bước giải:

a) (-5x^3)(2x^2-7xy+5y^2)

= -10x^5+35x^4y-25x^3y^2

b) 4x^3(3x^2+5x-6)

=12x^5+20x^4-24x^3

c)(-1/2xy^2)(4x^2y-6xy+8xy^2+11)

=-2x^3y^3+3x^2y^3-4x^2y^4-5,5xy^2

d)(1/5x^2y^3)(-5/4xy^2+3y-5)

=-1/4x^3y^5+3/5x^2y^4-1x^2y^3

bài2

a)1(1-4x+16x^2)+4x(1-4x+16x^2)

=1-4x+16x^2+4x-16x^2+64x^3

=1+64x^3

b)(3x^2-2x)(6x^2-4x+5)

=3x^2(6x^2-4x+5)-2x(6x^2-4x+5)

=18x^4-12x^3+15x^2-12x^3+8x^2-10x

18x^4+23x^2-10x

c)(3xy-1/2)(4xy^2-6x^2y+1)

=3xy(4xy^2-6x^2y+1)-1/2(4xy^2-6x^2y+1)

=12x^2y^3-18x^3y^2+3xy-2xy^2+3x^2y-1/2

d)(xy^2-2/3)(6xy^2-15xy+9)

=xy^2(6xy^2-15xy+9)-2/3(6xy^2-15xy+9)

=6x^2y^4-15x^2y^3+9xy^2-4xy+10xy-6