Question

By what number should ${\left(\frac{1}{2}\right)}^{-1}$ be multiplied so that the product may be equal to ${\left(-\frac{4}{7}\right)}^{-1}?$

Answer 1

Using the property a⁻¹ = 1/a for every natural number a, we have (1/2)⁻¹ = 2 and (−4/7)⁻¹ = −7/4. We have to find a number x such that
$2x=\frac{-7}{4}$
Dividing both sides by 2, we get:
$x=\frac{-7}{8}$
Hence, the required number is −7/8.