Tentukan penyelesaian sistem persamaan berikut dengan metode eliminasi! 1. x + y = 10 dan x – y = 2 2. x + y = 7 dan x – y = 1 3. x + 2y = 3 dan x + 3y = 4 4. x

1) x + y = 10
x - y = 2
-----------------(-)
2y = 8
y = 4
• x + y = 10
x - y = 2
----------------(+)
2x = 12
x = 6
hp = ( 6, 4)

2) x + y = 7
x - y = 1
----------------(-)
2y = 6
y = 3
• x + y = 7
x - y = 1
---------------(+)
2x = 8
x = 4
hp = ( 4,3 )

3) x + 2y = 3
x + 3y = 4
-----------------(-)
- y = - 1
y = 1
• x + 2y = 3 |×3
x + 3y = 4 |×2
maka
3x + 6y = 9
2x + 6y = 8
------------------(-)
x = 1
hp = ( 1 , 1 )

4) x - y = 6
2x + y = 18
-----------------(+)
3x = 24
x = 8
• x - y = 6 |×2
2x + y = 18
maka
2x - 2y = 12
2x + y = 18
----------------(-)
- 3y = - 6
y = 2
hp = ( 8 , 2 )

5) 2x + y = 5 |×2
3x - 2y = 11
maka
4x + 2y = 10
3x - 2y = 11
------------------(+)
7x = 21
x = 3
• 2x + y = 5 |×3
3x - 2y = 11 |×2
maka
6x + 3y = 15
6x - 4y = 22
------------------(-)
7y = - 7
y = - 1
hp = ( 3 , - 1 )

1. x+y=10
x-y=2
_______ -
2y=8
y=4
x-4=2
x=4+2=6

2. x+y=7
x-y=1
_______-
2y=6
y=3
x-3=1
x=3+1=4

3. x+2y=3
x+3y=4
_________-
-y=-1
y=1

x+3.1=4
x=4-3=1

4. x-y=6
2x+y=18
________-
-x=-12
x=12

2.12+y=18
24+y=18
y=18-24
y=-6

5. 2x+y=5 |x2
3x-2y=11 |x1
_________
4x+2y=5
3x-2y=11
_________+
7x=16
x=16/7= 2 2/7

3. 16/7 -2y=11
7-2y=11
-2y=11-7
-2y=4
y=-2