1.已知:X+Y+Z=3Y=2Z,求X/X+Y+Z的值 2.已知:1/X-1/Y=3,求2X+3XY-2Y/X-2XY-Y的值这是创新提高的题,我不太会做!
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![1.已知:X+Y+Z=3Y=2Z,求X/X+Y+Z的值 2.已知:1/X-1/Y=3,求2X+3XY-2Y/X-2XY-Y的值这是创新提高的题,我不太会做!](/uploads/image/z/571625-17-5.jpg?t=1.%E5%B7%B2%E7%9F%A5%EF%BC%9AX%2BY%2BZ%3D3Y%3D2Z%2C%E6%B1%82X%2FX%2BY%2BZ%E7%9A%84%E5%80%BC+2.%E5%B7%B2%E7%9F%A5%EF%BC%9A1%2FX-1%2FY%3D3%2C%E6%B1%822X%2B3XY-2Y%2FX-2XY-Y%E7%9A%84%E5%80%BC%E8%BF%99%E6%98%AF%E5%88%9B%E6%96%B0%E6%8F%90%E9%AB%98%E7%9A%84%E9%A2%98%2C%E6%88%91%E4%B8%8D%E5%A4%AA%E4%BC%9A%E5%81%9A%21)
1.已知:X+Y+Z=3Y=2Z,求X/X+Y+Z的值 2.已知:1/X-1/Y=3,求2X+3XY-2Y/X-2XY-Y的值这是创新提高的题,我不太会做!
1.已知:X+Y+Z=3Y=2Z,求X/X+Y+Z的值 2.已知:1/X-1/Y=3,求2X+3XY-2Y/X-2XY-Y的值
这是创新提高的题,我不太会做!
1.已知:X+Y+Z=3Y=2Z,求X/X+Y+Z的值 2.已知:1/X-1/Y=3,求2X+3XY-2Y/X-2XY-Y的值这是创新提高的题,我不太会做!
1.
z=3y/2
把:z=3y/2代入x+y+z=3y
得:x+y+3y/2=3y
整理后得:x=y/2
所以:x/(x+y+z)=(y/2)/(y/2+y+3y/2)=1/6
2.
因为1/x-1/y=3,则1/y-1/x=-3
(2x+3xy-2y)/(x-2xy-y) (分子分母同时除以xy)
=(2/y+3-2/x)/(1/y-2-1/x)
=(2/y-2/x+3)/(1/y-1/x-2)
=(-2*3+3)/(-3-2)
=-3/-5
=3/5
1、1/6 假设x=1,y=2,z=3
2、3/5
我也不会做
第一题答案是1/6 第二题是3/5(不知道有没算错,哈)