diketahui persamaan linier tiga variabel sebagai berikut : 4x-y+2z =5 5x-10z=5 4x+y-z=3 Nilai dari 4x+4y+4z adalah......... A. -2 B. 2 C. 1 D. 0 E. -1 (tolong c

4x - y + 2z = 5
5x - 10z = 5
4x + y - z = 3

4x + y - z = 3
- z = 3 - 4x - y
z = 4x + y - 3

5x - 10z = 5
5x - 10(4x + y - 3) = 5
5x - 40x - 10y + 30 = 5
- 35x - 10y = 5 - 30
- 35x - 10y = - 25

4x - y + 2z = 5
4x - y + 2(4x + y - 3) = 5
4x - y + 8x + 2y - 6 = 5
12x + y = 5 + 6
12x + y = 11

- 35x - 10y = - 25|× 1
12x + y = 11|× 10

- 35x - 10y = - 25
120x + 10y = 110
____________+
85x = 85
x = 1

12x + y = 11
12 + y = 11
y = 11 - 12
y = - 1

z = 4x + y - 3
z = 4 - 1 - 3
z = 0

x = 1
y = - 1
z = 0

4x + 4y + 4z
= 4 - 4 + 0
= 0

Jawaban : D. 0

Maaf Kalau Salah