Jika 3x-y=15 dan x+3y =3 maka hasil dari x-2y =... Help me ^_^ Kelas 8 Please

x + 3y = 3
x = 3 - 3y

3x - y = 15
3(3 - 3y) - y = 15
9 - 9y - y = 15
-10y = 15 - 9
-10y = 6
y = -6/10

x = 3 - 3y
x = 3 - 3(-6/10)
x = 3 + 18/10
x = 30/10 + 18/10
x = 48/10

x - 2y
48/10 - 2(-6/10)
48/10 + 12/10
60/10
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