Question

Tolong dibantu ya kak :) terima kasih yg udh mau bantu jawab

Answer 1

X - y + 2z = -5
x + y - z = 3
___________-
-2y + 3z = -8

2x + y + z = -1 |×1
x + y - z = 3 |×2
__________-

2x + y + z = -1
2x + 2y - 2z = 6
_____________-
-y + 3z = -7

-2y + 3z = -8
-y + 3z = -7
__________-
-y = -1
y = 1

-y + 3z = -7
(subtitusikan nilai y)
-(1) + 3z = -7
-1 + 3z = -7
3z = -7 + 1
3z = -6
z = -6/3
z = -2

x + y - z = 3
(subtitusikan nilai y dan z)
x + (1) -(-2) = 3
x + 1 + 2 = 3
x + 3 = 3
x = 3 - 3
x = 0

jadi, x = 0 ; y = 1 ; dan z = -2

Answer 2

X-y+2z = -5 ...(1)
2x+y+z = -1 ...(2)
x+y-z = 3 ...(3)

Eliminasi salah satu variabel
x-y+2z = -5
2x+y+z = -1
__________+
3x+3z =-6 ...(4)

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

3x+3z = -6
x+2z = -4 ×3
__________-
3x+3z = -6
3x+6z = -12
__________-
-3z = 6
z = -2

Substitusikan x ke...(5)
x+2z = -4
-2+2z = -4
2z = -2
z = -1

Substitusikan x dan z ke ...(1)
x-y+2z = -5
-2-y+2(-1) = -5
-y-4 = -5
-y = -1
y = 1

Jadi, x = -2; y = 1; dan z = -1

Semoga membantu dan bisa dipahami serta jawabannya tepat.