Question

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

Answer 1

Let the number be = x

So,

5-1 × x = (-7)-1

1/5 × x = 1/-7 (1/an = a-n)

x = (-1/7) / (1/5)

= (-1/7) × (5/1) (1/a ÷ 1/b = 1/a × b/1)

= -5/7