1.a方/1+a-a+1（计算,求值）2.(1/a-2+1/a+2)除以2a/a方-4a+4,其中a=-4(先化简,在求值）3.已知X-3y=0（xy不等于0）,求2x+y/x方-2xy+y方*（x-y）的值4.x/x方-x+2=2x/x+1（解方程）

1.a方/1+a-a+1（计算,求值）2.(1/a-2+1/a+2)除以2a/a方-4a+4,其中a=-4(先化简,在求值）3.已知X-3y=0（xy不等于0）,求2x+y/x方-2xy+y方*（x-y）的值4.x/x方-x+2=2x/x+1（解方程）
1.a方/1+a-a+1（计算,求值）
2.(1/a-2+1/a+2)除以2a/a方-4a+4,其中a=-4(先化简,在求值）
3.已知X-3y=0（xy不等于0）,求2x+y/x方-2xy+y方*（x-y）的值
4.x/x方-x+2=2x/x+1（解方程）

1.a方/1+a-a+1（计算,求值）2.(1/a-2+1/a+2)除以2a/a方-4a+4,其中a=-4(先化简,在求值）3.已知X-3y=0（xy不等于0）,求2x+y/x方-2xy+y方*（x-y）的值4.x/x方-x+2=2x/x+1（解方程）
1.
a²/(1+a)-a+1
= a²/(a+1)-(a-1)
= [a²-(a+1)(a-1)]/(a+1)
= [a²-(a²-1)]/(a+1)
= 1/(a+1) .
2.
[1/(a-2)+1/(a+2)]/[2a/(a²-4a+4)]
= {[(a+2)+(a-2)]/(a+2)(a-2)}/[2a/(a-2)²]
= [2a/(a+2)(a-2)]*[(a-2)²/2a]
= (a-2)/(a+2) ,
∵ a= -4 ,
∴ (a-2)/(a+2)
= (-4-2)/(-4+2)
= 3 .
3.
[(2x+y)/(x²-2xy+y²)]*(x-y)
= [(2x+y)/(x-y)²]*(x-y)
= (2x+y)/(x-y) ,
∵ x-3y=0（xy不等于0）,
∴ x=3y ,
∴ (2x+y)/(x-y)
= (6y+y)/(3y-y)
= 7/2 .
（PS：因不明确原式如何,所以结果未必对.但解题方法与过程类似.）
4.
x/(x²-x+2)=2x/(x+1) ,
x/[(x-2)(x+1)]=2x/(x+1) ,
1/(x-2)=2 ,
2(x-2)=1 ,
2x-4=1 ,
∴ x=5/2 .

1/(a+1)

1.
a²/(1+a)-a+1
= a²/(a+1)-(a-1)
= [a²-(a+1)(a-1)]/(a+1)
= [a²-(a²-1)]/(a+1)
= 1/(a+1) 。
2.
[1/(a-2)+1/(a+2)]/[2a/(a²-4a+4)]
=...

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1.
a²/(1+a)-a+1
= a²/(a+1)-(a-1)
= [a²-(a+1)(a-1)]/(a+1)
= [a²-(a²-1)]/(a+1)
= 1/(a+1) 。
2.
[1/(a-2)+1/(a+2)]/[2a/(a²-4a+4)]
= {[(a+2)+(a-2)]/(a+2)(a-2)}/[2a/(a-2)²]
= [2a/(a+2)(a-2)]*[(a-2)²/2a]
= (a-2)/(a+2) ，
∵ a= -4 ，
∴ (a-2)/(a+2)
= (-4-2)/(-4+2)
= 3 。
3.
[(2x+y)/(x²-2xy+y²)]*(x-y)
= [(2x+y)/(x-y)²]*(x-y)
= (2x+y)/(x-y) ，
∵ x-3y=0（xy不等于0），
∴ x=3y ，
∴ (2x+y)/(x-y)
= (6y+y)/(3y-y)
= 7/2 。
（PS：因不明确原式如何，所以结果未必对。但解题方法与过程类似。）
4.
x/(x²-x+2)=2x/(x+1) ,
x/[(x-2)(x+1)]=2x/(x+1) ,
1/(x-2)=2 ,
2(x-2)=1 ,
2x-4=1 ,
∴ x=5/2 。
祝你进步！

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1.
a²/(1+a)-a+1
= a²/(a+1)-(a-1)
= [a²-(a+1)(a-1)]/(a+1)
= [a²-(a²-1)]/(a+1)
= 1/(a+1) 。
2.
[1/(a-2)+1/(a+2)]/[2a/(a²-4a+4)]
=...

全部展开

1.
a²/(1+a)-a+1
= a²/(a+1)-(a-1)
= [a²-(a+1)(a-1)]/(a+1)
= [a²-(a²-1)]/(a+1)
= 1/(a+1) 。
2.
[1/(a-2)+1/(a+2)]/[2a/(a²-4a+4)]
= {[(a+2)+(a-2)]/(a+2)(a-2)}/[2a/(a-2)²]
= [2a/(a+2)(a-2)]*[(a-2)²/2a]
= (a-2)/(a+2) ，
∵ a= -4 ，
∴ (a-2)/(a+2)
= (-4-2)/(-4+2)
= 3 。
3.
[(2x+y)/(x²-2xy+y²)]*(x-y)
= [(2x+y)/(x-y)²]*(x-y)
= (2x+y)/(x-y) ，
∵ x-3y=0（xy不等于0），
∴ x=3y ，
∴ (2x+y)/(x-y)
= (6y+y)/(3y-y)
= 7/2 。
（PS：因不明确原式如何，所以结果未必对。但解题方法与过程类似。）
4.
x/(x²-x+2)=2x/(x+1) ,
x/[(x-2)(x+1)]=2x/(x+1) ,
1/(x-2)=2 ,
2(x-2)=1 ,
2x-4=1 ,
∴ x=5/2 。
祝你进步！快乐

收起