第1个回答 2020-01-17
1、(x-y)^3
=(x-y)(x-y)
^2
=(x-y)(x^2-2xy+y^2)
=x^3-2x^2y+xy^2-x^2y+2xy^2-y^3
=x^3-3x^2y+3xy^2-y^3
2、(x-y)^4=(y-x)^4
=(x-y)(x-y)
^2(x-y)
=(x^3-3x^2y+3xy^2-y^3)(x-y)
=x^4-3x^3y+3x^2y^2-xy^3-x^3y+3x^2y^2-3xy^3+y^4
=x^4-4x^3y+6x^2y^2-4xy^3+y^4
这么解题好像没有啥意思!!!是不是要算下面两种哦!
3、(x-y)^3*(y-x)^4
=(x-y)^3*(x-y)^4
=(x-y)^7
4、(x-y)^3*/(y-x)^4
=(x-y)^3*/(x-y)^4
=1/(x-y)