To complete the problem (5.2 - 4.5) - 5.5(4.8) you have to start with solving the numbers inside of the ( )'s.
Once you do this you should get .7 - 5.5(4.8).
Then you need to multiply to get .7 - 26.4.
Now all you have to do is simplify, -25.7
There you go! If you have any more questions about this or anything else just let me know! ;)