Question

Diketahui sistem persamaan linear 2x + 3y + z = 1, x + 2y + 3z = 5, 3x + y + 2z = 6
hitung nilai 4x+3y+2z (dengan cara)

Answer 1

Materi PLTV
Kelas X

2x + 3y + z = 1 
x + 2y + 3z = 5 
3x + y + 2z = 6

(i) Eliminasi
2x + 3y + z = 1
2x + 4y + 6z = 10 
_______________ - 
       -y - 5z = -9
        y + 5z = 9
(ii) Eliminasi
3x + 6y + 9z = 15
3x + y + 2z = 6
______________ - 
       5y + 7z = 9
(iii) Eliminasi
y + 5z = 9 (x5)

5y + 25z = 45
5y + 7z = 9
____________ - 
       18z = 36
           z = 2

5y + 7z = 9
5y = -5
y = -1

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

4x + 3y + 2z
4(1) + 3(-1) + 2(2)
4 + (-3) + 4
5