I read the article on this site on the topic of translating word problems, as well as the part of my math book on it, but I've got a few problems that I just can't seem to translate. Could anyone help, please?

1st problem:

The sum of two numbers is 42. One number plus 2 times the other number is 57. What are the two numbers?

My math teacher helped me translate it, and he said that it would be written as 57=(42-y)-2y, but I think he made a mistake translating it or I did in solving it, because I keep coming up with y = -5 and the answer key said it should be y = 15

Here's how I tried to do it:

57 = (42-y) - 2y

57 = 42 - 3y

15 = 3y

-5 = y

Does anybody know what went wrong here?

And if you're not too sick of me by now, I have another word problem that I really can't translate at all.

2nd problem:

The difference between two numbers is -38. Two times the smaller number minus five times the larger number is -217. What are the two numbers?

Any help would be greatly appreciated, and sorry for asking you guys to help me with all this at once. ^^;