Question

17．已知|x+y-3|+（x-2y）²=0，则（　　）

• A． $\left\{\begin{array}{l}{x=-1}\\{y=-2}\end{array}\right.$
• B． $\left\{\begin{array}{l}{x=-2}\\{y=-1}\end{array}\right.$
• C． $\left\{\begin{array}{l}{x=2}\\{y=1}\end{array}\right.$
• D． $\left\{\begin{array}{l}{x=1}\\{y=2}\end{array}\right.$

Answer 1

分析 根据非负数的性质，得到$\left\{\begin{array}{l}{x+y-3=0}\\{x-2y=0}\end{array}\right.$，解二元一次方程组即可解答．

解答 解：∵|x+y-3|+（x-2y）²=0，
∴$\left\{\begin{array}{l}{x+y-3=0}\\{x-2y=0}\end{array}\right.$，
解得：$\left\{\begin{array}{l}{x=2}\\{y=1}\end{array}\right.$
故选：C．

点评 本题考查了解二元一次方程组，解决本题的关键是根据非负数的性质，得到$\left\{\begin{array}{l}{x+y-3=0}\\{x-2y=0}\end{array}\right.$．