1.2(x-y)-3x=4
3(x-y)+15y=12
2.x/3-2y=3
2x+y=5
要好似e個人咁答
3x - 2y = 2 ...... (1)
x - y / 2 = - 4 ...... (2)
From (2), x = - 4 + y / 2 ...... (3)
Sub. (3) into (1),
3 ( - 4 + y / 2 ) - 2y = 2
- 12 + 3y / 2 - 2y = 2
3y / 2 - 2y = 14
- y / 2 = 14
- y = 28
y = -28
Sub. y = - 28 into (3),
x = - 4 + ( - 28 ) / 2
x = - 4 -14
x = -18
更新1:
sorry第1題打錯 1.2(x+y)-3x=4 3(x-y)+5y=12 x=2,y=3 我要步驟
