懂的来!具体看补充!(-2m-n)(2m-n)^2(2m+n)^2计算a^(n+2)-4a^n+16a^(n-2)(x-y)^2-4(x-y-1)第二第三个是因式分解

(-2m-n)(2m-n)^2(2m+n)^2
=-(2m+n)*(2m+n)^2*(2m-n)^2
=-(2m+n)^3*(2m-n)^2
(2)
a^(n+2)-4a^n+16a^(n-2)
=a^(n-2)*(a^4-4a^2+16)
化简不了了
(3)
(x-y)^2-4(x-y-1)
=(x-y)^2-4(x-y)+4
=(x-y+2)^2