(x+y)/3=2.(1)
(x+y)/3=(3x+4y)/5.(2)
由(2)得
9x+12y=5x+5y
4x+7y=0
x=-(7/4)y
代入(1)得
x+y=6
-(7/4)y+y=6
-(3/4)y=6
y=-8
则
x=-(7/4)y
=-(7/4)*(-8)
=14
解得
x=14
y=-8