设集合A={={(x,y)| 2x-3y=1},B={(x,y)| 2x-y=3},C={(x,y)|ax+y=11},若A∩B=A∩C,求实数a的值

问题描述:

设集合A={={(x,y)| 2x-3y=1},B={(x,y)| 2x-y=3},C={(x,y)|ax+y=11},若A∩B=A∩C,求实数a的值

2x - 3y = 1
2x - y = 3
解得:
x = 2
y = 1
所以 A∩B = {(2 ,1)}
把 (2 ,1)代入 ax + y = 11 得:
2a + 1 = 11
a = 5