三、計算題:每題10分,共20分(須寫出完整的
計算過程)
1、解下列各二元一次聯立方程式: ~20
3x-4y-5=2(x+y+3)
(1)
3 (2x-y+1)=4x-5y-3
3x-4-5-2x+2y+6 ""@
111
L6x-3y+3=4x-54-31110
DX2-61-8y-10-4x+44 +121110
③-=-51-13=9y+15
-14y=28,y=-2
3X18-5-2x-416-
X=-5
(5分)
A1652)
3x+y x-y
3
5
3x-2
y+5
4
2
解:
· 15x+5)=3x-3y110
(5分)
6x-4=4y+2011)
00:12x=-8y, 6x=-4Y
-41-4=4y+20
-8y=24,y=-3
6x=12,x=2 A=12,-3
231111-
若|x+2y-8|+(3x+y+3)+(2x5y+k)=0,則
(65)
(1) x-y= ? 9x+y+9+4x+25y+k
13x+26y+9+k=0
L13x+26y+9+k=01118 Caa+y+91
解:
-x+2y-8=0...0
5x+2y-8110
13x4264-104=0.1
x2=18x+24
1131+26+9=-1 3-0=11x
③②:17X
S1=-=-K=113
K=113
(2) k= ?
FEE
1x+27-8=014
+3x+26y+9+1 = 0111
13x+26y-104-0111③
=13x+26y+9=-K
-=-113
K=113
A=113
(4分
