Dijawab dong yang no. 8 ( 15 poin kalau benar )

y = x + 5
x + 3y = 15

x + 3y = 15
x + 3(x + 5) = 15
x + 3x + 15 = 15
4x = 15 - 15
4x = 0
x = 0

y = x + 5
y = 0 + 5
y = 5

x - y
= 0 - 5
= - 5

Jawaban : B. - 5

Maaf Kalau Salah