3x-3y=k+1/2 (1)
3x+y=2k-3 (2)
(2)*3-(1)
9x+3y-3x+3y=6k-9-k-1/2
6x+6y=5k-19/2
x+y=8
所以6x+6y=6*8=48
所以5k-19/2=48
5k=48+19/2=115/2
k=23/2
3x-3y=k+1/2 (1)
3x+y=2k-3 (2)
(2)*3-(1)
9x+3y-3x+3y=6k-9-k-1/2
6x+6y=5k-19/2
x+y=8
所以6x+6y=6*8=48
所以5k-19/2=48
5k=48+19/2=115/2
k=23/2