Firstmy math question....

I am asked to solve this

I followed these examples Systems of Equations - Solve by addition or subtraction and thus this occurred...

cancel the s and I'm left with

Now to solve for

I plug in into the second equation

cancel...

and

Ok now that I have the s and the s I plug those into the first equation....right so far?!

Did I do this right?! if not, then where did I go wrong, I have a hard time with these types of equations because I can never figure out elimination/addition nor graphing!!

NOW FOR MY SECOND QUESTIONwhat has happened to theMessage:options that used to be above the text box!?

Many thanks!!!