Answer:
The given expression can be written as -1=19(-1)+18.
Explanation:
According to quotient remainder theorem:
For any integer a and a positive integer d, there exist unique integers q and r such that

It can also written as

The given expression is

Here a=-1 and d=19.


If -1 is divides by 19, then the remainder is 18. The value of r is 18.
Therefore the given expression can be written as -1=19(-1)+18.