Everything is correct... Either your book's answer is wrong or you have copied the question incorrectly.
could some please help with the following question.
The remainder when is dividied by is five times more that when it is divided by .
As far as i can see ( i remember to set x to a value that makes divisor 0 since dividend=divisor x quotient + remainder) :
must be doing something stupid because the book says the answer is -3