分解因式：(1)x^4-4x+3 (2)1+(b-a^2)x^2-abx^3 （3）a^3+3a^2+3a+b^3+3b

(1)x^2-4x+3= (x-1)(x-3)
(2)1+(b-a^2)x^2-abx^3
=1-a²x²+bx²-abx^3
=(1-ax)(1+ax)+bx²(1-ax)
=(1-ax)(1+ax+bx²)
（3）a^3+3a^2+3a+b^3+3b^2+3b+2
=(a^3+3a²+3a+1)+(b^3+3b²+3b+1)
=(a+1)^3+(b+1)^3
=(a+b+2)[(a+1)²-(a+1)(b+1)+(b+1)²]
=(a+b+2)(a²-ab+b²+a+b+1)
(4)a^4+a^2b^2+b^4
=(a²+b²)²-(ab)²
=(a²+ab+b²)(a²-ab+b²)
(5)-a^4-b^4-c^4+2a^2b^2+2b^2c^2+2c^2a^2
=-[a^4+2a²b²+b^4-2a²c²-2b²c²+c^4-4a²b²]
=-[(a²+b²)²-2c²(a²+b²)+c^4-(2ab)²]
=-[(a²+b²-c²)²-(2ab)²]
=-(a²+2ab+b²-c²)(a²-2ab+b²-c²)
=-[(a+b)²-c²][(a-b)²-c²]
=-(a+b+c)(a+b-c)(a-b+c)(a-b-c)

(1)x^2-4x+3
= (x-1)(x-3)
(2)1+(b-a^2)x^2-abx^3

(1)x^4-4x+3 = (x-1)(x-3)十字相乘法
(2)1+(b-a^2)x^2-abx^3 =1-a²x²+bx²-abx^3=(1-ax)(1+ax)+bx²(1-ax)=(1-ax)(1+ax+bx²)
（3）a^3+3a^2+3a+b^3+3b^2+3b+2 =(a^3+3a²+3a+1)+(b...

1、原式=x^4－x³＋x³－x²＋x²－x－3x＋3
=﹙x－1﹚﹙x³＋x²＋x－3﹚
=﹙x－1﹚﹙x³－x²＋2x²－2x＋3x－3﹚
=﹙x－1﹚²﹙x²＋2x＋3﹚。
2、原式=1＋bx²－a²x²－a...