tolong dijawab beserta carany yaa...makasihh

Kelas 8 Matematika
Bab SPLDV

2x - y = -10
y = 2x + 10

-3x + 2y = 8
-3x + 2 (2x + 10) = 8
-3x + 4x + 20 = 8
x = 8 - 20
x = -12

y = 2x + 10
y = 2 . (-12) + 10
y = -24 + 10
y = -14

a - 2b
= -12 - 2 . (-14)
= -12 + 28
= 16