题目内容
11.若方程组$\left\{\begin{array}{l}{2a-3b=m}\\{3a+5b=n}\end{array}\right.$的解是$\left\{\begin{array}{l}{a=3}\\{b=-1}\end{array}\right.$,则方程组$\left\{\begin{array}{l}{2(x-1)-3(y+2)=m}\\{3(x-1)+5(y+2)=n}\end{array}\right.$的解是$\left\{\begin{array}{l}{x=4}\\{y=-3}\end{array}\right.$.分析 由方程组$\left\{\begin{array}{l}{2a-3b=m}\\{3a+5b=n}\end{array}\right.$和方程组$\left\{\begin{array}{l}{2(x-1)-3(y+2)=m}\\{3(x-1)+5(y+2)=n}\end{array}\right.$可知,a=x-1,b=y+2,由$\left\{\begin{array}{l}{a=3}\\{b=-1}\end{array}\right.$,可以求得x、y的值,本题得以解决.
解答 解:∵方程组$\left\{\begin{array}{l}{2a-3b=m}\\{3a+5b=n}\end{array}\right.$和方程组$\left\{\begin{array}{l}{2(x-1)-3(y+2)=m}\\{3(x-1)+5(y+2)=n}\end{array}\right.$,
∴x-1=a,y+2=b,
∵方程组$\left\{\begin{array}{l}{2a-3b=m}\\{3a+5b=n}\end{array}\right.$的解是$\left\{\begin{array}{l}{a=3}\\{b=-1}\end{array}\right.$,
∴$\left\{\begin{array}{l}{x-1=3}\\{y+2=-1}\end{array}\right.$,
解得$\left\{\begin{array}{l}{x=4}\\{y=-3}\end{array}\right.$.
故答案为:$\left\{\begin{array}{l}{x=4}\\{y=-3}\end{array}\right.$.
点评 本题考查二元一次方程组的解,解题的关键是运用整体的数学思想解答问题.
| A. | 1 | B. | 4 | C. | 8 | D. | 16 |
| A. | 2013 | B. | 2014 | C. | 2015 | D. | 2016 |