Question

2x + y = 8 ...(1)
y + 3z = 5 ...(2)
z +2w = 1 ...(3)
5w + 3x = 9 ...(4)

x=
y=
z=
w=
Tolong dijawab pakai cara ya.....

Answer 1

X = 2
y = 4
z = 1
w = 2
karena, 2.2 + 4 = 8

Answer 2

2x+y = 8 ......(1)
y+3z = 5 ....(2)
z+2w = 1 ...(3)
5w+3x = 9 ...(4)

(1) dan (2)
2x+y = 8
y+3z = 5
__________(kurangkan)
2x-3z = 3 ...(5)

(3) dan (4)
z+2w = 1 | kali 5
-------------------------
5w+3x = 9 | kali 2

5z+10w = 5
10w+6x = 18
___________(kurangkan)
5z-6x = -13
6x-5z = 13 ...(6)

(5) dan (6)
2x-3z = 3 | kali 3
---------------------
6x-5z = 13 | kali 1

6x-9z = 9
6x-5z = 13
__________(kurangkan)
-4z = -4
z = 1

substitusi z = 1 ke (5) didapat
2x-3(1) = 3
2x-3 = 3
2x = 6
x = 3

substitusi z = 1 ke (2) didapat
y+3(1) = 5
y+3 = 5
y = 2

substitusi z = 1 ke (3) didapat
1+2w = 1
2w = 0
w = 0

jadi
x = 3
y = 2
z = 1
w = 0