How do you find the additive and multiplicative inverse of -5/8?

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Answer 1 · 2017-03-26T19:38:42

Additive inverse, $5/8$
Multiplicative inverse, $-8/5$

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 $a = -5/8$
It's additive inverse be $c$ .

Then $-5/8 + c = 0$

Now, adding $5/8$ to both sides,

$c = 5/8$ .

Let the multiplicative inverse be $b$ .

Then $a*b = 1$
$implies -5/8*b = 1$

Multiplying both sides with $-8/5$

$b = -8/5$