已知A=(+1)÷+ (1)化简A; (2)当x=﹣1时,求A的值; (3)若A=1,

已知A=+1÷+

1)化简A

2)当x=1时,求A的值;

3)若A=1,求x的值.

答案

【考点】分式的化简求值.

【专题】计算题;分式.

【分析】1)原式括号中两项通分并利用同分母分式的加法法则计算,同时利用除法法则变形,约分后两项通分并利用同分母分式的减法法则计算即可得到结果;

2)把x的值代入计算即可求出值;

3)由A=1,求出x的值即可.

【解答】解:(1A===

2)当x=1时,A==22

3)若A=1,得方程=1

去分母,得2x4=x+1

移项,得2xx=4+1

合并同类项,得x=5

经检验x=5是原方程的解.

【点评】此题考查了分式的化简求值,熟练掌握运算法则是解本题的关键.

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