meili 发表于 2022-10-27 16:00:42

已知(3a-b)/(2b-a)=7,(x+y)/(2x-y)=5,求(ax-2by)/(ax+2by)的值.

<p>问题:已知(3a-b)/(2b-a)=7,(x+y)/(2x-y)=5,求(ax-2by)/(ax+2by)的值.
<p>答案:↓↓↓<p class="nav-title mt10" style="border-top:1px solid #ccc;padding-top: 10px;">马凤英的回答:<div class="content-b">网友采纳  (3a-b)/(2b-a)=7  3a-b=14b-7a  10a=15b  a=3b/2  (x+y)/(2x-y)=5  x+y=10x-5y  9x=6y  ∴x=2y/3  ∴ax=3b/2×2y/3=by  ∴(ax-2by)/(ax+2by)  =(by-2by)/(by+2by)  =-1/3
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