tentukan penyelesaian sistem persamaan berikut dengan sistem eliminasi! a. x+y=10 dan x-y=4 b.x-2y=9 dan 2x+2y=6 c.2x+3y=-1 dan 4x+3y=7

a.
x + y = 10
x - y = 4
________-
2y = 6
y = 6/2 = 3

mencari nilai x
x + y = 10
x + 3 = 10
x = 10 - 3
x = 7

b.
x - 2y = 9. | x2| 2x - 4y = 18
2x + 2y = 6 | x | 2x + 2y = 6

2x-4y =18
2x+2y=6
_______-
-6y = 12
y = 12/6
y = 2

nilai x
2x + 2y = 6
2x + 4 = 6
2x = 6-4
2x = 2
x = 2/2 =1

c.
2x + 3y =-1 |x4| 8x +12y = -4
4x +3y = 7 |x2| 8x + 6y = 14

8x +12y = -4
8x + 6y = 14
_________-
6y = -18
y = 18/6 =3

mencari nilai x
2x + 3y =-1
2x + 9y = -1
2x =-1-9
2x =-10
x = -10/2 = -5