已知x2-5-1999=0,求代数式(x-2)³-(x-1)²+1除以x-2的值
问题描述:
已知x2-5-1999=0,求代数式(x-2)³-(x-1)²+1除以x-2的值
答
x2-5-1999=0应该改为x2-5x-1999=0过程如下:
((x-2)³-(x-1)²+1)/(x-2)=(x-2)^2-((x-1)^2-1)/(x-2)=(x-2)^2-x(x-2)/(x-2)=x^2-4x+4-x=x^2-5x+4
∵x^2-5x-1999=0
∴x^2-5x=1999
∴((x-2)³-(x-1)²+1)/(x-2)=1999+4=2003.