Question

14．二元一次方程组$\left\{\begin{array}{l}{x=3}\\{2x-y=8}\end{array}\right.$的解是$\left\{\begin{array}{l}{x=3}\\{y=-2}\end{array}\right.$．

Answer 1

分析 方程组利用代入消元法求出解即可．

解答 解：$\left\{\begin{array}{l}{x=3①}\\{2x-y=8②}\end{array}\right.$，
把①代入②得：6-y=8，
解得：y=-2，
则方程组的解为$\left\{\begin{array}{l}{x=3}\\{y=-2}\end{array}\right.$，
故答案为：$\left\{\begin{array}{l}{x=3}\\{y=-2}\end{array}\right.$

点评 此题考查了解二元一次方程组，熟练掌握运算法则是解本题的关键．