Jawab dengan serius... Hitunglah SPLTV berikut, menggunakan metode gabungan (eliminasi-subtitusi) 5x + y + 4z = -8 3x + y + 4z = -6 2x - 3y + z = -6

Bab SPLTV
Matematika SMA Kelas X

5x + y + 4z = -8
3x + y + 4z = -6
---------------------- -
              2x = -2
                x = -1

3x + y + 4z = -6 → dikali 3 menjadi → 9x + 3y + 12z = -18

2x - 3y +     z =   -6
9x + 3y + 12z = -18
---------------------------- +
11x + 13z = -24
11 . (-1) + 13z = -24
13z = -24 + 11
z = -13/13
z = -1

3x + y + 4z = -6
3 . (-1) + y + 4 . (-1) = -6
-3 + y - 4 = -6
y = -6 + 7
y = 1

Jadi, x = -1
        y = 1
        z = -1

Materi : SPLTV



5x + y + 4z = -8 ........................(1)
3x + y + 4z = -6 ........................(2)
2x - 3y + z = -6 .........................(3)

dari (1) dan (2)
5x + y + 4z = -8
3x + y + 4z = -6
------------------------ (-)
2x = -2
x = -1

sehingga

5(-1) + y + 4z = -8 ........................(1)
3(-1) + y + 4z = -6 ........................(2)
2(-1) - 3y + z = -6 .........................(3)
menjadi
y + 4z = -3 ........................(1)
y + 4z = -3 ........................(2)
-3y + z = -4 .........................(3)

dari (2) dan (3)
3y + 12z = -9
-3y + z = -4
------------------- (+)
      13z = -13
         z = -1

-3y + z = -4
-3y + (-1) = -4
-3y = -3
y = 1

jadi HP : {(-1,1,-1)}