解：由1/x-1/y=1,变形两边各乘以xy，得，y-x=3xy,∴xy=1/3(y-x),（2x-14xy-2y）/（x-2xy-y）=[2x-14/3(y-x)-2y]/ [ x-2/3(y-x)-y) ],分式上下中此悄各乘以3，卖渣并展开括号，得3(2x-14/3y+14/3x-2y)/3(x-2/3y+2/3x-y)=(6x-14y+14x-6y)/(3x-2y+2x-3y)=(20x-20y)/(5x-5y)=4(5x-5y)/(5x-5y)=4 祝学习进步扒洞
已知1/x-1/y=3，求代数式2x-14xy-2y/x-2xy-y的值
Simone
发布于 2023-05-03 05:15:43
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