已知x/y=3/5.则在(1)(x-y)/(x+y)=1/4(2)(x+3)/(y+5)=3/5(3)x/(x+2y)=
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已知x/y=3/5.则在(1)(x-y)/(x+y)=1/4(2)(x+3)/(y+5)=3/5(3)x/(x+2y)=3/13(4)(x+y)/x=8/3这四个
这四个成不成立、、
这四个成不成立、、
![已知x/y=3/5.则在(1)(x-y)/(x+y)=1/4(2)(x+3)/(y+5)=3/5(3)x/(x+2y)=](/uploads/image/z/19777455-63-5.jpg?t=%E5%B7%B2%E7%9F%A5x%2Fy%3D3%2F5.%E5%88%99%E5%9C%A8%EF%BC%881%EF%BC%89%EF%BC%88x-y%29%2F%28x%2By%29%3D1%2F4%EF%BC%882%EF%BC%89%28x%2B3%29%2F%28y%2B5%29%3D3%2F5%EF%BC%883%EF%BC%89x%2F%28x%2B2y%29%3D)
因为:x/y=3/5
所以:设:x=3k,y=5k
所以:x-y=-2k,x+y=8k,
x+3=3k+3=3(k+1),y+5=5k+5=5(k+1)
x+2y=13k
所以:(1)错误;其余正确
所以:设:x=3k,y=5k
所以:x-y=-2k,x+y=8k,
x+3=3k+3=3(k+1),y+5=5k+5=5(k+1)
x+2y=13k
所以:(1)错误;其余正确
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