Question

X + y = 1/9
y + z = 2/9
z + x = 5/9

x = ?, y = ?, z = ?, semua jawabannya pecahan
Tolong dibantu pakai cara ya...

Answer 1

X+y = 1/9 ...(1)
y+z = 2/9 ...(2)
z+x = 5/9 ...(3)

(2) dan (3)
y+z = 2/9
z+x = 5/9
________(kurangka)
y-x = -3/9
x-y = 3/9 ...(4)

(1) dan (4)
x+y = 1/9
x-y = 3/9
_______(kurangkan)
2y = -2/9
y = -1/9

substitusi y = -4/9 ke (1) didapat
x+(-1/9) = 1/9
x = 1/9 +1/9
x = 2/9

substitusi y = -1/9 ke (2) didapat
y+z = 2/9
-1/9+z = 2/9
z = 2/9+1/9 = 3/9

jadi,
x = 2/9
y = -1/9
z = 3/9

Answer 2

Jumlahin semua soalnya, hasilnya :
2x + 2y + 2z = 8/9
x+y+z = 4/9

tinggal subtitusi saja..
x+(y+z)=4/9
x+(2/9) = 4/9
x = 4/9 - 2/9 = 2/9

x+y+z =4/9
y+(x+z) = 4/9
y + 5/9 = 4/9
y = -1/9

x+y+z = 4/9
(x+y) + z = 4/9
1/9 + z = 4/9
z = 3/9