I'm trying to teach myself how to simplify expressions and I'm having trouble with these two:

1. x - 2(9 + 6x)

2. 2(x - y)

I have been told that the answers are:

1. -11x -18

2. 2x - 2y

... but I have no idea how to get those answers.

This is how I tried to simplify them:

1. x - 2(9) + x - 2(6x)

2. 2(x) + 2(-y)

I think that is not right, but I don't understand what I'm doing wrong. How do you simplify these?

Thanks for any help.