若当k为何整数时,方程组{x+2y=k+1,2x+5y=k-1的解才满足x>y且x-y

x+2y=k+1,2x+5y=k-1则y=-k-3,x=3k+7
x>y,则k>-5/2
x-y所以,只有k=0,-1,-2,