Respuesta :
There is nothing to do with it. If it gives you x=# or y=# then you can plug it in, but otherwise, this is the simplest way to write this equation.
If you want to go further, you can figure out that
y= 7-x
but that's about it.
If you want to go further, you can figure out that
y= 7-x
but that's about it.