tolong dibantu pakai cara jawabnya terima kasih

25.
y - x = - 1
x + 2y = 7

y - x = - 1
y = - 1 + x
y = x - 1

x + 2y = 7
x + 2(x - 1) = 7
x + 2x - 2 = 7
3x = 7 + 2
3x = 9
x = 3

y = x - 1
y = 3 - 1
y = 2

y + 2x
= 2 + 6
= 8

Jawaban : a. 8

Maaf Kalau Salah

y - x = -1
x = 1+ y

x + 2y = 7
1 + y + 2y = 7
1 + 3y = 7
3y = 7-1
y = 6/3
y= 2
x + 2y =7
x +2(2) =7
x = 7-8
x = -1

y + 2x
2 + 2(-1) = 0