已知4x-3y=6z 2x+4y=14z 求2xy/x^+y^
已知4x-3y=6z 2x+4y=14z 求2xy/x^+y^
数学人气：146 ℃时间：2019-10-11 05:02:35
优质解答
4x-3y=6z 28x-21y=42z2x+4y=14z6x+12y=42z28x-21y=6x+12y28x-6x=12y+21y22x=33y2x=3yx/y=3/22xy/(x^2+y^2)分子分母同时除以y^2=(2xy/y^2)/(x^2/y^2+y^2/y^2)=(2x/y)/(x^2/y^2+1)=(2*3/2)/[(3/2)^2+1]=3/(9/4+1)=3/(1...
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