Jika x dan y memenuhi persamaan 5x - 3y = 20 dan 3x - 5y = 4,maka 6x - 4y adalah..... Select one: A. 20 B. 46 C. 63 D. 23

5x - 3y = 20 (×3)
3x - 5y = 4. (×5)
_____________
15x - 9y = 60
15x - 25y = 20
_____________-
0 + 16y = 40
y = 40/16 = 5/2 = 2,5

5x - 3y = 20
5x - (3×2,5) = 20
5x - 7,5 = 20
5x = 20-7,5 = 12,5
x = 12,5/5 = 2,5

6x - 4y = (6×2,5) - (4×2,5) = 15 - 10 = 5