'Both' just emphasises that both things are true. You might want to add emphasis if it is unexpected that both can be true at the same time. As such, you can use it or not, the basic meaning stays the same, it's the more subtle message that changes.

I had trouble with my driving on the way to the Company, but both my car and I are OK! 2、As our typewriters are made of a mix of light and hard alloy, they are both portable and durable.