Question

Diket sistem persamaan x+y+z=6, 4x+2y+z=7, dan 9x+3y+z=12. nilai x-y-z adalah?

bantuin pls!!

Answer 1

Verified answer

x + y + z = 6 ...............................(1)
4x + 2y + z = 7 ............................(2)
9x + 3y + z = 12 ..........................(3)

dari (3) dan (2)
9x + 3y + z = 12
4x + 2y + z = 7
---------------------- (-)
5x + y + 0z = 5 ....................................(4)

dari (4) dan (2)
5x + y + 0z = 5
4x + 2y + z = 7
--------------------- (-)
x - y - z = -2

jadi
x - y - z = -2