1.若3x-2y=0,则(x+y):(x-y)=______

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1.若3x-2y=0,则(x+y):(x-y)=______1.若3x-2y=0,则(x+y):(x-y)=______1.若3x-2y=0,则(x+y):(x-y)=______-5,设a(x+y)

1.若3x-2y=0,则(x+y):(x-y)=______
1.若3x-2y=0,则(x+y):(x-y)=______

1.若3x-2y=0,则(x+y):(x-y)=______
-5,设a(x+y)+b(x-y)=3x-2y,对应的去括号,合并同类项后可以得到:a=b-3,a-b=2,解这个方程组可以得到,a=1/2,b=5/2,所以由式:(x+y)/(x-y)+b/a=a(x+y)+b(x-y)/a(x-y)=0;所以:(x+y)/(x-y)+b/a=0,所以(x+y)/(x-y)=-b/a=-5.仔细看看能看懂的.

5:1!X得2@Y得3

-5

3x-2y=0
3x=2y
x=2/3y
x+y = 2/3y+y = 5/3y
x-y = 2/3y-y = -1/3y
(x+y) :(x-y)= -5

我也8年纪,这道题不该不会吧。3X=2Y,所以X=2/3 Y,代入,得(2\3Y+Y):(2\3 y-y),自己接着算吧,得-5,分给我,我同学

5:-1
3x=2y ==> x=2y/3
x+y= 2/3y+y = 5y/3
x-y= -y/3
所以 (x+y):(x-y) = 5y/3 : -y/3 = 5:-1 = -5

没看懂
:什么意思?

5:-1 3x=2y x=2/3y 代值就OK啦

将3x-2y=0化成:3x+3y=5y 与 3x-3y=-y 两个方程,两方程进而可分别化为:3(x+y)=5y 与 3(x-y)=-y,再将此两个方程式相除可得:3(x+y):3(x-y)=5y:-y ,即得值为-5。