因式分解:①x^3-5x^2-6x②a^2-b^2-2b-1-查字典问答网
分类选择

来自谈静的问题

  因式分解:①x^3-5x^2-6x②a^2-b^2-2b-1化简:[x-(x+1分之2x)]除以x^2-1分之x^2-2x+1先化简,再求值:(a+b)(a-b)+(a+b)平方-2a平方,其中a=3,b=-3分之1

  因式分解:①x^3-5x^2-6x②a^2-b^2-2b-1化简:[x-(x+1分之2x)]除以x^2-1分之x^2-2x+1

  先化简,再求值:(a+b)(a-b)+(a+b)平方-2a平方,其中a=3,b=-3分之1

1回答
2020-01-1612:55
我要回答
提示:回答问题需要登录哦!
马雁

  解(1)x³-5x²-6x

  =x(x²-5x-6)

  =x(x-6)(x+1)

  ②a²-b²-2b-1

  =a²-(b²+2b+1)

  =a²-(b+1)²

  =(a+b+1)(a-b-1)

  3.[x-2x/(x+1)]÷(x²-2x+1)/(x²-1)

  =[x(x+1)-2x]/(x+1)÷(x-1)²/(x+1)(x-1)

  =(x²-x)/(x+1)÷(x-1)/(x+1)

  =x(x-1)/(x+1)÷(x-1)/(x+1)

  =x

  4.:(a+b)(a-b)+(a+b)²-2a²

  =a²-b²+a²+2ab+b²-2a²

  =2ab

  =2×3×(-1/3)

  =-2

2020-01-16 12:59:31
大家都在问
最新问答