### A good answer might be:

>     The positive integer: 0000 0110     ( 610 )

>     Reflect each bit:     1111 1001

>     Add one:              1111 1010     ( -610 )

# Negative Six Again

This resulted in the same repn for minus six as we figured out before. Here is what is going on: When each bit of a pattern is reflected then the two patterns added together make all 1's. This works for all patterns:

>           0110 1010   pattern
>           1001 0101   pattern reflected
>           ---------
>           1111 1111   all columns filled

Adding one to this pattern creates a pattern of all zero's:

>          11111 111    row of carry bits
>           1111 1111   all columns filled
>           0000 0001   one
>           ---------
>           0000 0000

But instead, the one is added to the "pattern reflected."

>     pattern +  pattern reflected               = all ones

>     pattern +  pattern reflected + one         = all zeros

>     pattern + (pattern reflected + one )       = all zeros

>     pattern + (two's complement of pattern)    = all zeros

Don't be too upset if the above is confusing. Mostly all you need is to get used to this stuff. Of course, this takes practice.

### QUESTION 18:

What is the two's complement of 0100 0111?