2x-4y=0

-x+2y=1

trying to solve

So you have your equations: 2x-4y=0 and - x+2y=1

Depending on the variable you want to take out, depends on how your equation will be set up, but, I'm going to take out X.

With the first equation you subtract 2x from 0 which leaves you with - 4y=-2

Divide the sum and you get a positive 2x.

Plug 2 into X on the following equation, it should look like this. - 2+2y=1. This time you're trying to find Y so, add 2 to 1 and you get 2y=3. Divide this and it should give you a decimal.