Question

这道分式题怎么做？急！！！！

化简求值

x/(x-1)-3/(x-1)(x+2)-1

x=-（2/3）

速度！！！

Answer 1

x/(x-1)-3/(x-1)(x+2)-1
=x(x+2)/(x-1)(x+2)-3/(x-1)(x+2)-(x-1)(x+2)/(x-1)(x+2)
=[x(x+2)-3-(x-1)(x+2)]/(x-1)(x+2)
=[x^2+2x-3-(x-1)(x+2)]/(x-1)(x+2)
=[(x+3)(x-1)-(x-1)(x+2)]/(x-1)(x+2)
=(x-1)[(x+3)-(x+2)]/(x-1)(x+2)
=(x-1)(x+3-x-2)/(x-1)(x+2)
=(x-1)/(x-1)(x+2)
=1/(x+2)
=1/(-2/3+2)
=1/(4/3)
=3/4

Answer 2

3/40

Answer 3

第一个分式分子分母乘（x-1）第三个分子分母乘(x-1)(x+2) 再分式相加 上面的分子是x(x-1)(x+2)-3-(x-1)(x+2) 拆开再因式分解得(x-1)(x+2)(x+3)和分母相约就可以了

Answer 4

x/(x-1)-3/(x-1)(x+2)-1
=x*(x+2)/[(x-1)(x+2)]-3/(x-1)(x+2)-1
=(x^2+2x-3)/(x-1)(x+2)-1
=(x+3)/(x+2)-1
=3/4

Answer 5

等于1吧....

Answer 6

通分
(x^2+2x-3)/(x-1)(x+2) -1
分子提出x-1消去 剩下的不写了