How do I simplify the following expressions by collecting like terms?

2x-9+x=?
6x-4j+3y=?
4x+15+2x-x+9+?
j-k-j+3k=
5r+3r+4rt=
7yz+yz=

2 answers

If you answer the question I posed for you in your last question, I'll be happy to help you with these questions.
Oh sorry that is what it said but what you put was right

Thank you =]