题目内容
10.已知关于x,y的方程组$\left\{\begin{array}{l}{{a}_{1}x+{b}_{1}y={c}_{1}}\\{{a}_{2}x+{b}_{2}y={c}_{2}}\end{array}\right.$的解是$\left\{\begin{array}{l}{x=3}\\{y=4}\end{array}\right.$,则方程组$\left\{\begin{array}{l}3{{a}_{1}x+2{b}_{1}(y-1)={c}_{1}}\\{3{a}_{2}x+2{b}_{2}(y-1)={c}_{2}}\end{array}\right.$的解为$\left\{\begin{array}{l}{x=1}\\{y=3}\end{array}\right.$.分析 根据二元一次方程组的解的定义得到3x=3,2(y-1)=4,于是得到结论.
解答 解:∵方程组$\left\{\begin{array}{l}3{{a}_{1}x+2{b}_{1}(y-1)={c}_{1}}\\{3{a}_{2}x+2{b}_{2}(y-1)={c}_{2}}\end{array}\right.$可化为$\left\{\begin{array}{l}{{a}_{1}•3x+{b}_{1}•2(y-1)={c}_{1}}\\{{a}_{1}•3x+{b}_{2}•2(y-1)={c}_{2}}\end{array}\right.$,
∵方程组$\left\{\begin{array}{l}{{a}_{1}x+{b}_{1}y={c}_{1}}\\{{a}_{2}x+{b}_{2}y={c}_{2}}\end{array}\right.$的解是$\left\{\begin{array}{l}{x=3}\\{y=4}\end{array}\right.$,
∴3x=3,2(y-1)=4,
∴x=1,y=3,
∴方程组$\left\{\begin{array}{l}3{{a}_{1}x+2{b}_{1}(y-1)={c}_{1}}\\{3{a}_{2}x+2{b}_{2}(y-1)={c}_{2}}\end{array}\right.$的解为$\left\{\begin{array}{l}{x=1}\\{y=3}\end{array}\right.$,
故答案为:$\left\{\begin{array}{l}{x=1}\\{y=3}\end{array}\right.$.
点评 本题考查了二元一次方程组的解,熟练掌握二元一次方程组的解的定义是解题的关键.
| A. | 40° | B. | 30° | C. | 25° | D. | 20° |
| A. | y=-2x2 | B. | y=2x2 | C. | y=-0.5x2 | D. | y=0.5x2 |
| A. | 44° | B. | 46° | C. | 54° | D. | 56° |
| A. | 第一象限 | B. | 第二象限 | C. | 第三象限 | D. | 第四象限 |