Of course. Bit patterns can represent anything symbolic.
The question is silly. There is nothing mysterious about representing signed numbers with bit patterns. Here is another silly question:
Is it possible to represent a fraction with a whole number of bits?
Of course. Recall the fourth advantage of binary: anything that can be represented with patterns can be represented with bit patterns. It is just a matter of picking a bit pattern for each fraction you wish to represent. There are several systematic ways to do this. This chapter discusses some of them.
In the decimal value 12.6 what power of 10 is associated with: