Question

What is the product of any integer and –1?

Answer 1

it will be the negative of that integer. For example, 5*-1 = -5

Answer 2

The integer's opposite form meaning if you multiply a negative integer with -1, you get the same integer in its positive form.
Ex: -2 x -1 = 2
If you multiply a positive integer with -1, you get the same integer in its positive form.
Ex: 2 x -1 = -2