Question

1/a-x-1/a+x-2x/a^2+x^2-4x^3/a^4+x^4+8x^7/x^8-a^8

Answer 1

1/（a-x）-1/（a+x）-2x/a^2+x^2-4x^3/a^4+x^4+8x^7/x^8-a^8

=2x/(a^2-x^2)-2x/(a^2+x^2)-4x^3/a^4+x^4+8x^7/x^8-a^8

=4x^3/(a^4-x^4)-4x^3/(a^4+x^4)+8x^7/x^8-a^8

=8x^7/(a^8-x^8)+8x^7/(x^8-a^8)

=8x^7/(a^8-x^8)-8x^7/(a^8-x^8)

=0