Question

11．方程组$\left\{\begin{array}{l}{\frac{x-2}{2}-y=1}\\{y-x=-3}\end{array}\right.$的解是$\left\{\begin{array}{l}{x=2}\\{y=-1}\end{array}\right.$．

Answer 1

分析 方程组整理后，利用加减消元法求出解即可．

解答 解：方程组整理得：$\left\{\begin{array}{l}{x-2y=4①}\\{x-y=3②}\end{array}\right.$，
②-①得：y=-1，
把y=-1代入②得：x=2，
则方程组的解为$\left\{\begin{array}{l}{x=2}\\{y=-1}\end{array}\right.$．
故答案为：$\left\{\begin{array}{l}{x=2}\\{y=-1}\end{array}\right.$．

点评 此题考查了解二元一次方程组，利用了消元的思想，消元的方法有：代入消元法与加减消元法．