1..(x+y)^5*(-x-y)^4
=.(x+y)^5*(x+y)^4
=(x+y)^9
2..(-2)*(-2)^2*(-2)^3*...*(-2)^100
=(-2)^(1+2+...+99+100)
=(-2)^5050
=2^5050
3.(a-b)^2*(b-a)^5
=(b-a)^2*(b-a)^5
=(b-a)^7
4.3a^3*a^4+2a*a^2*(-a)^4+4a^2*(-a)^5
=3a^7+2a^7-4a^7
=a^7
1..(x+y)^5*(-x-y)^4
=.(x+y)^5*(x+y)^4
=(x+y)^9
2..(-2)*(-2)^2*(-2)^3*...*(-2)^100
=(-2)^(1+2+...+99+100)
=(-2)^5050
=2^5050
3.(a-b)^2*(b-a)^5
=(b-a)^2*(b-a)^5
=(b-a)^7
4.3a^3*a^4+2a*a^2*(-a)^4+4a^2*(-a)^5
=3a^7+2a^7-4a^7
=a^7