因式分解：a平方+5ab+6b平方+a+2b；x四次方-2x平方+5x-4

a2+5ab+6b2+a+2b
=(a+2b)(a+3b)+(a+2b)
=(a+2b)(a+3b+1)
x4-2x2+5x-4
=(x2-1)2+(5x-5)
=(x+1)2(x-1)2+5(x-1)
=(x-1)[(x+1)2(x-1)+5]
=(x-1)[ x3+2x2+x -x2-2x-1+5]
=(x-1)(x3+x2-x+4)

1、
原式=(a+2b)(a+3b)+(a+2b)
=(a+2b)(a+3b+1)
2、
原式= x^4-2x²+1+5x-5
=(x²-1)²-5(x-1)
=(x+1)²(x-1)²-5(x-1)
=(x-1)[(x²+2x+1)(x-1)-5]
=(x-1)(x³+x²-x-6)

a^2＋5ab＋6b^2＋a＋2b＝(a＋2b)(a＋3b)＋(a＋2b)＝(a＋2b)(a＋3b＋1)x^4－2x^2＋5x－4 ＝x^4－2x^2＋1＋5x－5＝(x^2－1)^2＋5(x－1)＝(x＋1)^2(x－1)^2＋5(x－1)＝(x－1)[(x＋1)^2(x－1)＋5]＝(x－1)[(x^2－1)(x＋1...

a平方+5ab+6b平方+a+2b=(a+2b)(a+3b)+a+2b=(a+2b)(a+3b+1)
x四次方-2x平方+5x-4=x^4-3x^2+2+x^2+5x-6=(x-1)(x+1)(x^2-2)+(x+6)(x-1)=(x-1)(x^3+x^2-x+4)