Section 1.1
Divisors and multiples
We know how to add integers, how to subtract them and how to multiply them. Division is a bit harder.
Definition
Let a
Z and b
Z.
- We call b a
divisor of a
if there is an
integer q Z such that a = qb.
- If b is a nonzero divisor of a, then the (unique) integer q with a = qb is called the quotient a over b and denoted by a/b.
If b is a divisor of a, we also say that
We write this as b | a.