Question

因式分解(ab+cd)(a^2-b^2+c^2-d^2)+(ac+bd)(a^2+b^2-……

Answer 1

=a^3b-ab^3+abc^2-abd^2+a^2cd-b^2cd+c^3d+cd^3+a^3c+ab^2c-ac^3-acd^2+a^2bd+b^3d-c^2bd-bd^3

=a^3(b+c)+b^3(d-a)+c^3(d-a)-d^3(b+c)+abc(b+c)-abd(d-a)-acd(d-a)-bcd(b+c)

=(b+c)(a^3-d^3+abc-bcd)+(d-a)(...