(m^2+n^2)^2-4m^2n^2-(8a^2+2b^2)+64a^2b^24a^2b^2-(a^2+b^2-c^2)^25(a+b)+a+bx-y+m(x-y)a(b+a)-b-1ab-b-(a-1)记住!

Question

(m^2+n^2)^2-4m^2n^2
-(8a^2+2b^2)+64a^2b^2
4a^2b^2-(a^2+b^2-c^2)^2
5(a+b)+a+b
x-y+m(x-y)
a(b+a)-b-1
ab-b-(a-1)
记住!

Answer 1

(m^2+n^2)^2-4m^2n^2 =m^4+2m^2n^2+n^4-4m^2n^2=m^4-2m^2n^2+n^4
=(m^2-n^2)^2
(8a^2+2b^2)+64a^2b^2 (你少打了个平方吧?）
4a^2b^2-(a^2+b^2-c^2)^2 =4a^2b^2-a^4-2a^2b^2-2a^2b^2-b^4+2(a^2+b^2)c^2-c^4=-(c^2-a^2+b^2)(c^2+a^2-b^2)
5(a+b)+a+b =6(a+b)
x-y+m(x-y) =(x-y)(1+m)
a(b+a)-b-1=ab+a^2-b-1=b(a-1)+(a+1)(a-1)=(b+a+1)(a-1)
ab-b-(a-1) =b(a-1)-(a-1)=(b-1)(a-1)