2x-3y=26 dan 3x-4y=36 nilai x + 2y

I. 3x – 4y = 36
3x = 36 + 4y
x = 12 + 4/3 y

II. 2x – 3y = 26
2(12 + 4/3 y) – 3y = 26
24 + 8/3 y – 3 y = 26
8/3 y – 3 y = 2
-1/3 y = 2
y = -6

III. x = 12 + 4/3y
x = 12 + 4/3 (-6)
x = 12 + (-8)
x = 4

IV. x + 2y = 4 + 2 (-6)
= 4 – 12
= -8