题目下列方程组是二元一次方程组的是（ ）A.{4x−y=−2y=2x+3\left\{\begin{array}{l}4x-y=-2\\ y=2x+3\end{array}\right.{4x−y=−2y=2x+3B.{1x−1=y=y3x+y=0\left\{\begin{array}{l}\frac{1}{x}-1=y=y\\ 3x+y=0\end{array}\right.{x1−1=y=y3x+y=0C.{x−y=1xy=2\left\{\begin{array}{l}x-y=1\\ xy=2\end{array}\right.{x−y=1xy=2D.{x2−x−2=0y=x+1\left\{\begin{array}{l}x^{2}-x-2=0\\ y=x+1\end{array}\right.{x2−x−2=0y=x+1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
