I need to explain how positive and negative integers can be combined under the operations of addition and multiplication using mod 5. I need to give examples of how I could use this in addition using positive numbers and then negative numbers. I also need to describe how to use this in multiplication using positive and then negative numbers.
I have read so many different materials on mod and am still having incredible difficulty figuring this out.
Oct 9th 2008, 07:41 AM
First you can make every integers including the negative one to be 0,1,2,3, or 4 modulo 5.
since -63=-65+2=5(-13)+2, then -63=2 modulo 5.
Then one you translate every integer into either 0,1,2,3 or 4 then addition and multiplication are basically addition and multiplication involving 0,1,2,3,4 only.