How do you find the additive and multiplicative inverse of -8?

Question

24603 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-03-26T19:42:19

Additive inverse, $+8$
Multiplicative inverse, $-1/8$

For a number $a$ , it's multiplicative inverse $b$ is such that $a*b = 1$ which is the multiplicative identity.

For a number $a$ , it's additive inverse $c$ would be such that $a + c = 0$ where $0$ is additive identity.

Thus, for $a = -8$
It's additive inverse be $c$ .

Then $-8 + c = 0$

Now, adding $8$ to both sides,

$c = 8$ .

Let the multiplicative inverse be $b$ .

Then $a*b = 1$
$implies -8*b = 1$

Multiplying both sides with $-1/8$

$b = -1/8$