Question

问几道初二分式的加减、 急!!!! 求各位啦！！！！ 帮帮忙啊！！！！ 感激不尽~~~~

1.(x/x+y+2y/x+y)·xy/x+2y÷(1/x+1/y).
2.(1/a+1/b)²÷(1/a²－1/b²).
3.(3x²/4y)².2y/3x+x²/2y²÷2y²/x.
4.(a+b/a－b)².2a－2b/3a+3b－a²/a²－b²÷a/b.

Answer 1

1.(x/(x+y)+2y/(x+y))·xy/(x+2y)÷(1/x+1/y).
=(x+2y)/（x+y)*xy/(x+2y)*xy/（x+y)
=x²y²/(x+y)²
2.(1/a+1/b)²÷(1/a²－1/b²).
=(a+b)²/a²b²÷（b²-a²)/a²b²
=-(a+b)²/a²b²*a²b²/(a+b)(a-b)
=-（a+b）/(a-b)
3.(3x²/4y)².2y/3x+x²/2y²÷2y²/x.
=9x^4/16y²*2y/3x+x³/4y^4
=3x³/8y+x³/4y^4
=(3x³y³+2x³)/8y^4
4.(a+b/a－b)².（2a－2b）/（3a+3b）－a²/a²－b²÷a/b.
=（a+b)²/（a-b）²*.2（a－b）/3（a+b）-a²/（a²－b²）÷a/b
=2（a+b)/3（a-b）-ab/(a²-b²）
=2（a+b)²/3（a²-b²）-3ab/3(a²-b²）
=（2a²+ab+2b²)/3(a²-b²)

Answer 2

根据我的经验，你的题不严格 该加括号的没有加
所以你最好重新发一遍 主意括号

追问

1.(x/x+y+2y/x+y) · xy/x + 2y÷ (1/x+1/y).
2.(1/a+1/b)²÷ (1/a²－1/b²).
3.(3x²/4y)² . 2y/3x + x²/2y² ÷ 2y²/x.
4.(a+b/a－b)² . 2a－2b/3a+3b － a²/a²－b² ÷a/b.
注带点的是乘号“.” “/”这个代表 分数线

追答

c

Answer 3

不会啊

Answer 4

没法做 你的题是这样的吧 这样的题目还要我们去猜
x/（x+y+2y）/[（x+y) · xy]/[x + 2y÷ (1/x+1/y)]