1. tentukan himpunan penyelesaian dengan metode eliminasi= a. 2x+y=7 x-4y=10 b. x+6y=-1 3x+2y=13 c. 4x+y=-3 2x-5y=-7

Jawab :
a)
2x+y=7...........(x1)
x-4y=10..........(x2)

2x + y = 7
2x - 8y = 20
-------------------- -
9y = -13
y = -13/9

2x+y=7............(x4)
x-4y=10...........(x1)

8x + 4y = 28
x - 4y = 10
--------------------- +
9x = 38
x = 38/9