Metode Subsitusi X -3y = 1 2y - x =7

x - 3y = 1 ... (1)
2y - x = 7 ... (2)

(1)
x - 3y = 1
x = 3y + 1

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

(1)
x - 3y = 1
x - 3(-8) = 1
x + 24 = 1
x = 1 - 24
x = -23

Semoga membantu ^^