初一五道奥赛题1.若x/3=y/2=z/5.则分式(xy+xz+yz)/(x^2+y^2+z^2)值为?2.阅读 x+1/x=c+1/c解为x1=c.x2=1/cx+2/x=c+2/c解为x1=c.x2=2/cx+3/x=c+3/c解为x1=c.x2=3/c······（1）观察并猜想.x+m/x=c+m/c (m不等于0) .解并验证你

初一五道奥赛题1.若x/3=y/2=z/5.则分式(xy+xz+yz)/(x^2+y^2+z^2)值为?2.阅读 x+1/x=c+1/c解为x1=c.x2=1/cx+2/x=c+2/c解为x1=c.x2=2/cx+3/x=c+3/c解为x1=c.x2=3/c······（1）观察并猜想.x+m/x=c+m/c (m不等于0) .解并验证你
初一五道奥赛题
1.若x/3=y/2=z/5.则分式(xy+xz+yz)/(x^2+y^2+z^2)值为?
2.阅读 x+1/x=c+1/c解为x1=c.x2=1/c
x+2/x=c+2/c解为x1=c.x2=2/c
x+3/x=c+3/c解为x1=c.x2=3/c
······
（1）观察并猜想.x+m/x=c+m/c (m不等于0) .解并验证你的结论.
（2）利用这个结论解关于x的方程x+2/(x-1)=a+2/(a-1)
3.(1)若1/x+1/y=2.则(2x+3xy+2y)/(x+y+2xy)值是?
(2)若b/a+a/b=2.则(a^2+ab+b^2)/(a^2+4ab+b^2)值是?
4.已知3x-4y-z=0.2x+y-8z=0.求(x^2+y^2+z^2)/(xy+yz+2xz)值.
5若x
能写几道都行

初一五道奥赛题1.若x/3=y/2=z/5.则分式(xy+xz+yz)/(x^2+y^2+z^2)值为?2.阅读 x+1/x=c+1/c解为x1=c.x2=1/cx+2/x=c+2/c解为x1=c.x2=2/cx+3/x=c+3/c解为x1=c.x2=3/c······（1）观察并猜想.x+m/x=c+m/c (m不等于0) .解并验证你
1.设x/3=y/2=z/5=a,则x=3a,y=2a,z=5a,代入分式得结果31/38
2.(1).x1=c,x2=m/c,验证就是把x1,x2的值代入x+m/x=c+m/c；
(2).x+2/(x-1)=a+2/(a-1)→（x-1）+2/(x-1)=（a-1）+2/(a-1)→ x1-1=a-1,x2-1=2/(a-1)→x1=a,x2=(a+1)/(a-1)
3.(1).(2x+3xy+2y)/(x+y+2xy)→分子分母都除以xy→ （2/x+3+2/y）/(1/x+1/y+2)的结果7/4;
(2)b/a+a/b=2→等式两边乘以ab→a^2+b^2=2ab→a=b,代入的结果1/2
4.3x-4y-z=0,2x+y-8z=0→x=3z,y=2z,代入的结果1
5.不清楚

1.设 x/3=y/2=z/5=t 则 x=3t y=2t z=5t
带入得 (6t^2+15t^2+10t^2)/ (9t^2+4t^2+25t^2)=31/38
2.(1)x1=c.x2=m/c
将两根带入原方程即可证明
（2）两边同时减一，得
(x-1)+2/(x-1)=(a-1)+2/(a-1)
...

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1.设 x/3=y/2=z/5=t 则 x=3t y=2t z=5t
带入得 (6t^2+15t^2+10t^2)/ (9t^2+4t^2+25t^2)=31/38
2.(1)x1=c.x2=m/c
将两根带入原方程即可证明
（2）两边同时减一，得
(x-1)+2/(x-1)=(a-1)+2/(a-1)
利用上面结论得
x-1=a-1 或 x-1=2/(a-1)
即 x1=a x2=2/(a-1)+1=（a+1)/(a-1)
3.(1)(2x+3xy+2y)/(x+y+2xy) 分式上下同时除以 xy 得
（2/y + 3 +2/x)/(1/y + 1/x + 2 )
= 7/4
(2)(a^2+ab+b^2)/(a^2+4ab+b^2)分式上下同时除以 ab得
(a/b + 1 + b/a)/(a/b + 4 + b/a )
=3/6
=1/2
4. 3x-4y-z=0 2x+y-8z=0 解得
x=3z y=2z
代入得 (x^2+y^2+z^2)/(xy+yz+2xz)
=(9z^2 + 4z^2 + z^2 )/(6z^2 + 2z^2 + 6z^2)
=1

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