若方程组3x+y=k+1         的解为x,y,且x  > y,则k的取值范围是 _________ .

问题描述:

若方程组3x+y=k+1         的解为x,y,且x  > y,则k的取值范围是 _________ .                    x+3y=3                                                                                                                           

3x+y=k+1 (1)
x+3y=3 (2)
(1)-(2)
2x-2y=k-2
又x>y,即x-y>0,2(x-y)>0
故k-2>0
k>2