因式分解：1.（x2+x-6）(x2+x-8)-242.（x+1）(x-2)(x-3)(x-6)+203.(x+1)(x+2)(x+3)(x+6)-3x2第一小题的x2都为x的2次方，第三题的3x2为3乘以x的2次方

(1) (x^2+x+6)(x^2+x+8)-24
=(x^2=x)^2+14(x^2+x)+24
=(x^2+x+12)(x^2+x+20)
(2)（x+1）(x-2)(x-3)(x-6)+20
=[(x+1)(x-6)][(x-2)(x-3)]+20
=(x²-5x-6)(x²-5x+6)+20
设x²-5x=y
=(y-6)(y+6)+20
=y²-16
=(y+4)(y-4)
=(x²-5x+4)(x²-5x-4)
=(x-1)(x-4)(x²-5x-4)
(3)(x+1)(x+2)(x+3)(x+6)-3x2
=[(x+1)(x+6)][(x+2)(x+3)]-3x²
=（x²+7x+6)(x²+5x+6)-3x²
设x²+6x+6=y
=（y+x)(y-x)-3x²
=y²-x²-3x²
=（y+2x)(y-2x)
=(x²+8x+6)(x²+4x+6)
希望对你有帮助

1_(xx+x-7)"-25=(x-1)(x+2)(x-3)(x+4)
2_(xx-5x)"-16=(x-1)(x-4)*(xx-5x-4)实数还可分
3_(xx+6+6x)"-4xx=(x+2)(x+4)*(xx+4x+6)复数还可分

1.（x2+x-6）(x2+x-8)-24设x²+x-7=y原式=(y+1)(y-1）-24=y²-1-24=y²-25=(y+5)(y-5)=(x²+x-2)(x²+x-12)=(x+2)(x-1)(x+4)(x-3)2.（x+1）(x-2)(x-3)(x-6)+20=[(x+1)(x-6)][(x-2)(x-3)]+20=(x&...