How do you find the additive and multiplicative inverse of 1.5?

Question

9884 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-03-26T19:44:50

Additive inverse, $-1.5$
Multiplicative inverse, $2/3$ or $0.67$

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 $a = 1.5 = 3/2$
It's additive inverse be $c$ .

Then $3/2 + c = 0$

Now, adding $-3/2$ to both sides,

$c = -3/2 = -1.5$

Let the multiplicative inverse be $b$ .

Then $a*b = 1$
$implies 3/2*b = 1$

Multiplying both sides with $2/3$

$b = 2/3 = 0.67$