> 数学 >
化简分式x^2+2x+1分之x^2-1 - x-1分之x+1,并从-2,-1,0,1,2中选一个能使分式有意义的数代入求值
人气:262 ℃ 时间:2019-10-23 08:40:49
解答
解析:
由题意可知x≠1且x≠-1,那么:
(x^2+2x+1)分之(x^2-1) - (x-1)分之(x+1)
=(x+1)²分之(x+1)(x-1) - (x-1)分之(x+1)
=(x+1)分之(x-1) - (x-1)分之(x+1)
=(x²-1)分之[(x-1)²-(x+1)²]
=(x²-1)分之[(x²-2x+1)-(x²+2x+1)]
=(x²-1)分之(-4x)
不妨取x=0,那么:
(x^2+2x+1)分之(x^2-1) - (x-1)分之(x+1)
=(x²-1)分之(-4x)
=0
若取x=2,那么:
(x^2+2x+1)分之(x^2-1) - (x-1)分之(x+1)
=(4-1)分之(-8)
=-3分之8
推荐
猜你喜欢
© 2024 79432.Com All Rights Reserved.
电脑版|手机版