x*x*x*x+2008x*x+2007x+2008(提示:x*x*x-1=(x-1)*(x*x+x+1))
问题描述:
x*x*x*x+2008x*x+2007x+2008(提示:x*x*x-1=(x-1)*(x*x+x+1))
答
分解因式对吗?
记x*x*x=x³=x^3
x*x*x*x+2008x*x+2007x+2008=x^4+2008x²+2007x+2008
=x^4-x+2008x+2008x²+2008
=x(x³-1)+2008(x²+x+1)
=x(x-1)(x²+x+1)+2008(x²+x+1)
=(x²+x+1)[x(x-1)+2008]
=(x²+x+1)(x²-x+2008)
OK!