Question

Jika x + y + z = k
x + 2y + z = k
2x + y + z = k
k (tidak sama dengan) 0
maka nilai x^2 + y^2 + z^2 =....

Answer 1

X^2 + y^2 + z^2 = 0 + 0 + k^2
= k^2

Answer 2

X + y + z = k
x = k - y - z

x + 2y + z = k
x = k - 2y - z

x = x
k - y - z = k - 2y - z
k - y - z - k + 2y + z = 0
y = 0

lalu cari x

x + y + z = k
x + 0 + z = k
x + z = k
z = k - x

2x + y + z = k
2x + 0 + z = k
2x + z = k
z = k - 2x

z = z
k - x = k - 2x
k - x - k + 2x = 0
x = 0

x dan y sudah ketemu, tinggal cari z

x + y + z = k
0 + 0 + z = k
z = k

jadi,
x^2 + y^2 + z^2
= 0^2 + 0^2 + k^2
= k^2