1：(-x^n)^2+(x^2)^n-x^n*x^2 =x^2n+x^2n-x^(n+2)=2x^2n-x^(n+2)2：[(-n)^2]^5/[(-n*n^3)^2*2n^2]=[n^2]^5/[(-n^4)^2*2n^2]=[n^10]/[(n^8)*2n^2]=[n^10]/[2n^10]=1/2:3:-a*a^5-(a^2)^3-(-2a^3)^2=-a^6-(a^6)-(4a^6)=...