Question

By what number should 5⁻¹ be multiplied so that the product may be equal to (−7)⁻¹?

 

Answer 1

Expressing in fraction form, we get:
5⁻¹ = 1/5 (using the property a⁻¹ = 1/a)
and
(−7)⁻¹ = −1/7 (using the property a⁻¹ = 1/a).
We have to find a number x such that
`1/5x=(-1)/7`

Multiplying both sides by 5, we get: `x=-5/7`

Hence, 5⁻¹ should be multiplied by −5/7 to obtain (−7)⁻¹.