“凌君婕”您好,很高兴为您解答!解:2(A^2+B^2+C^2+AB+BC-AC)=(A^2+2AB+B^2)+(B^2+2BC+C^2))+(A^2-AC+C^2)=(A+B)^2+(B+C)^2+(A-C)^2=1+1+4=6A^2+B^2+C^2+AB+BC-AC=3因式分解:2a^n-50a^n+2 =2a^n(1-25^n)=2a^n(1-5a)(1+5a)希望我的回答对您有帮助~