(1)3x^2-[7x-(4x-3)-2x^2]
2个回答

俺不是高手,俺问问是因式分解么?

(1)3x^2-[7x-(4x-3)-2x^2]

=3x^2-7x+4x-3+2x^2

=5x^2-3x-3

(2)(2xy-y)-(-y+yx)

=2xy-y+y-xy

=xy

(3)5(a^2b-3ab^2)-2(a^2b-7ab^2)

=5a^2b-15ab^2-2a^2b+14ab^2

=3a^2b-ab^2

(4)11x^2+4x-1-x^2-4x-5

=10x^2-6

(5)(2x^4-4x^3y-2x^2y^2)-(x^4-2x^2y^2+y^3)+(-x^4+4x^3y-y^3)

=2x^4-4x^3y-2x^2y^2-x^4+2x^2y^2-y^3-x^4+4x^3y-y^3

=-2y^3