Tentukan selesaian dari sistem persamaan berikut. a.x+3y=5 dan -x-y=-3 b.4x+3y=-5 dan -x+3y=-10 c.2x+5y=16 dan 3x-5y=-1 d3x-2y=4 dan 6x-2y=-2 Dengan a dan b den

a) - x - y = - 3
- x = y - 3
x = - y + 3
subtitusi
x + 3y = 5
- y + 3 + 3y = 5
2y = 5 - 3
2y = 2
y = 1
subtitusi
x = - y + 3
x = - 1 + 3
x = 2
hp = ( 2, 1 )

b) - x + 3y = - 10
- x = - 3y - 10
x = 3y + 10
subtitusi
4x + 3y = - 5
4(3y + 10) + 3y = - 5
12y + 40 + 3y = - 5
15y = - 5 - 40
15y = - 45
y = - 3
subtitusi
x = 3y + 10
x = 3(-3) + 10
x = - 9 + 10
x = 1
hp = ( 1 , - 3)

c) 2x + 5y = 16
3x - 5y = - 1
---------------------(+)
5x = 15
x = 3
• 2x + 5y = 16 |×3
3x - 5y = - 1 |×2
maka
6x + 15y = 48
6x - 10y = - 2
---------------------(-)
25y = 50
y = 2
hp = ( 3,2 )

d) 3x - 2y = 4
6x - 2y = - 2
-------------------(-)
- 3x = 6
x = - 2
• 3x - 2y = 4 |×2
6x - 2y = - 2
maka
6x - 4y = 8
6x - 2y = - 2
------------------(-)
- 2y = 10
y = - 5
hp = ( - 2 , - 5 )