Question

14．若關(guān)于x、y的方程mx+ny=6的兩個解是$\left\{\begin{array}{l}{x=3}\\{y=2}\end{array}\right.$，$\left\{\begin{array}{l}{x=6}\\{y=6}\end{array}\right.$，則（　　）

• A． $\left\{\begin{array}{l}{m=-4}\\{n=-3}\end{array}\right.$
• B． $\left\{\begin{array}{l}{m=4}\\{n=-3}\end{array}\right.$
• C． $\left\{\begin{array}{l}{m=4}\\{n=3}\end{array}\right.$
• D． $\left\{\begin{array}{l}{m=-4}\\{n=3}\end{array}\right.$

Answer 1

分析 把方程的解代入方程可得到關(guān)于m、n的方程組，解方程組可求得答案．

解答 解：
∵關(guān)于x、y的方程mx+ny=6的兩個解是$\left\{\begin{array}{l}{x=3}\\{y=2}\end{array}\right.$，$\left\{\begin{array}{l}{x=6}\\{y=6}\end{array}\right.$，
∴$\left\{\begin{array}{l}{3m+2n=6}\\{6m+6n=6}\end{array}\right.$，解得$\left\{\begin{array}{l}{m=4}\\{n=-3}\end{array}\right.$，
故選B．

點評 本題主要考查二元一次方程解的定義，掌握方程的解滿足方程是解題的關(guān)鍵．