dik:2x-4y=9 dan 5y-4x=8. dit:himpunan penyelesaiannya?

2x + 4y = 9 dan 5y - 4x = 8
2x + 4y = 9
2x = -4y + 9
x = -4/2y + 9/2
x = -2y + 9/2

5y - 4x = 8
5y - 4 (-2y + 9/2) = 8
5y + 8y - 18 = 8
13y - 18 = 8
13y = 8 + 18
13y = 26
y = 26/13
y = 2

2x + 4 (2) = 9
2x + 8 = 9
2x = 9 - 8
2x = 1
x = 1/2

HP {1/2,2}