龙神花都第70章:问一道因式分解4

来源:百度文库 编辑:高校问答 时间:2024/05/13 03:43:22
(x^2+6x+8)(x^2+14x+48)+12

(x^2+6x+8)(x^2+14x+48)+12
=(x+4)(x+2)(x+6)(x+8)+12
=(x+4)(x+6)(x+2)(x+8)+12
=(x^2+10x+24)(x^2+10x+16)+12
=(x^2+10x)^2+40(x^2+10x)+16*24+12
=(x^2+10x)^2+40(x^2+10x)+396
=(x^2+10x+22)*(x^2+10x+18)
这个如果再继续的话
=(x^2+10x+25-3)*(x^2+10x+25-7)
=((x+5)^2-3)*((x+5)^2-7)
=(x+5+sqrt(3))*(x+5-sqrt(3))*(x+5+sqrt(7))*(x+5-sqrt(7))

sqrt(y)表示y开根号

(x^2+6x+8)(x^2+14x+48)+12
=(x+2)(x+4)(x+6)(x+8)+12
=(x^2+10x+16)(x^2+10x+24)+12
=(x^2+10x)^2+40(x^2+10x)+16×24+12
=(x^2+10x)^2+40(x^2+10x)+396
=(x^2+10x+22)(x^2+10x+18)