把下列各式分解因式：x⒉-4mx+8mn-4n⒉x⒊-11x⒉+31x-21x⒍-y⒍-2x⒊+1
问题描述：
把下列各式分解因式：
x⒉-4mx+8mn-4n⒉
x⒊-11x⒉+31x-21
x⒍-y⒍-2x⒊+1
答
D，第一题如果a
答
1.x^2-4mx+8mn-4n^2 =(x-2m)^2-(2m-2n)^2=(x-2n)(x-4m+2n)2.x^3-11x^2+31x-21=x^3-11x^2+10x+21x-21=x(x^2-11x+10)+21(x-1)=x(x-1)(x-10)+21(x-1)=(x-1)(x^2-10x+21)=(x-1)(x-3)(x-7)3.x^6-y^6-2x^3+1=(x^6-2x^3+1)-...