Jawaban:

x-y x-y

---- - z = -4 ---> --- = -4 + z ---> -28+7z-x+y=

7 7

-x+y+7z = 28 ----------> (1)

y+3z y+3z

2x + ------- = 11 ---> ------ = 11-2x --->

4 4

44-8x = y+3z ---> 8x+y+3z = 44 -----> (2)

x - z/5 = 3 ---> x-3 = z/5 ---> 5x-15 = z

5x-z = 15 ----> (3)

(1) dan (2) eliminir dl ;

-x+y+7z = 28

8x+y+3z= 44

-----------------_

-9x-4z = -16 ----------> (4)

dari persamaan (3) bisa didapat :

5x-z = 15 -----> z = 5x-15 ( nilai z nya substi

tusikan ke persamaan (4), maka didapat:

-9x-4(5x-15) = -16

-9x-20x+60 = -16

-29x = -16-60

-29x = -76

x = 76/29

x = 2,62

masukan nilai x ke persamaan:

z = 5x-15

z = 5(76/29) - 15

z = 13,10 - 15

z = -1,90

masukan nilai x dan z ke persamaan (1):

-x+y+7z = 28

-2,62 + y + 7(-1,90) = 28

y = 28 + 2,62 + 13,30

y = 43,92

ga tau ah keburu pusing !!