几道因式分解题.1.(x²+2x-3)(x²+2x-24)+902.x^4 -4x³+4x
1个回答

1.(x²+2x-3)(x²+2x-24)+90

=(x²+2x)²-27(x²+2x)+72+90

=(x²+2x)²-27(x²+2x)+162

=(x²+2x-18)(x²+2x-9)

2.x^4 -4x³+4x²-9

=(x²-2x)²-9

=(x²-2x+3)(x²-2x-3)

=(x²-2x+3)(x-3)(x+1)

3.(x-1)(x-2)(x-3)(x-4)-24

=[(x-1)(x-4)][(x-2)(x-3)]-24

=[(x²-5x)+4][(x²-5x)+6]-24

=(x²-5x)²+10(x²-5x)+24-24

=(x²-5x)(x²-5x+10)