题目已知非零有理数xxx,yyy满足x−3y=0x-3y=0x−3y=0,则x−2yx+2y=( )\frac{x-2y}{x+2y}=\left(\ \ \right)x+2yx−2y=( )A.−15-\frac{1}{5}−51B.−15y-\frac{1}{5y}−5y1C.15\frac{1}{5}51D.15y\frac{1}{5y}5y1知识点：解二元一次方程组——代入消元法章节：方程与不等式 / 二元一次方程组
