早教吧作业答案频道 -->数学-->
先化简,再求值:x^2+2x+1/x+2÷x^2-1/x-1-1-x-x^2/x+2,其中x=2014
题目详情
先化简,再求值:x^2+2x+1/x+2 ÷x^2-1/x-1 - 1-x-x^2/x+2,其中x=2014
▼优质解答
答案和解析
解
(x²+2x+1)/(x+2)÷(x²-1)/(x-1)-(1-x-x²)/(x+2)
=(x+1)²/(x+2)÷(x-1)(x+1)/(x-1)-(1-x-x²)/(x+2)
=(x+1)²/(x+2)×1/(x+1)-(1-x-x²)/(x+2)
=(x+1)/(x+2)-(1-x-x²)/(x+2)
=(x+1-1+x+x²)/(x+2)
=(x²+2x)/(x+2)
=x
=2014
(x²+2x+1)/(x+2)÷(x²-1)/(x-1)-(1-x-x²)/(x+2)
=(x+1)²/(x+2)÷(x-1)(x+1)/(x-1)-(1-x-x²)/(x+2)
=(x+1)²/(x+2)×1/(x+1)-(1-x-x²)/(x+2)
=(x+1)/(x+2)-(1-x-x²)/(x+2)
=(x+1-1+x+x²)/(x+2)
=(x²+2x)/(x+2)
=x
=2014
看了 先化简,再求值:x^2+2x...的网友还看了以下：