my mom and I can not figure this one out please help!!!! -(a-3b+27) I need to simplify.. Mom states it will be

-a+3b-27 I don't think you can do this Why would you just change the signs...

Your mom is correct. You distribute the negative sign to the rest of the equation but there are no common factors to be put together so, yes it would be -a+3b-27