Respuesta :
For any number x, when we multiply by -1/x, we get -x/x, or -1. As we haven't made any assumptions about x (other than x is not equal to zero, in which case x does not have a defined reciprocal), all negative reciprocals have a product of -1.
No matter what 'x' is, the negative reciprocal of 'x' is -(1/x).
Now let's multiply them:
(x) times -(1/x) = -(x/x) = -1 .
And there you are.
That's why.