Question

The multiplicative inverse of `-1 1/7` is ______.

Options

• `8/7`

• `(-8)/7`

• `7/8`

• `7/(-8)`

Answer 1

The multiplicative inverse of `-1 1/7` is `underlinebb(7/(-8))`.

Explanation:

We know that, if the product of two rational numbers is 1, then they are multiplicative inverse of each other.

Given number is `-1 1/7`, i.e. `(-8)/7`.

Let the multiplication inverse of `(- 8)/7` be x.

⇒ `(-8)/7 xx x = 1`

⇒ `x = 1 xx ((-7)/8)`    ...[By cross-multiplication]

= `(-7)/8` or `7/(-8)`

Hence, `(-7)/8` is the multiplicative inverse of `(-8)/7`.