Question 54262
To use the elimination method, you need to get an opposite of a coefficient with the same coefficient.
x + 2y = 0
2x + 4y = 0
-2x - 4y = 0
Now, combine that with the other equation:
2x + 5y = -1
-2x - 4y = 0
0x + 1y = -1
y = -1
Plug:
x + 2y = 0
x - 2 = 0
x = 2