please help, it's very urgent

Step-by-step explanation:
Divide by any number except 0 means the same as multiply by its inverse.
The inverse of [tex]a[/tex] is [tex]\dfrac{1}{a}[/tex]
Therefore
[tex]n\div(-1)=n\div\left(\dfrac{-1}{1}\right)=n\times\left(\dfrac{1}{-1}\right)=n\times(-1)=(-1)\times n=-1\times n[/tex]
Used the commutative property of multiplication: a × b = b × a
[tex]\huge\boxed{-1\times n=n\div(-1)}[/tex]