Jawapan

2016-03-18T11:13:30+08:00
2k - 3w = 10
2k = 10 + 3w
k = 5 + 3/2 w

substitute k

4k + w = -1
4( 5 + 3/2w) + w = -1
20 + 6w + w = -1
7w = -21
w = -3

when w = -3
k = 5 + 3/2w
k = 5 + 3/2(-3)
k = 1/2