Question

What is `\frac{5}{21} \div \frac{15}{7}`?

Answer 1

`5/21-:15/7=1/9`

Explanation:

Dividing by a fraction such as `a/b` is equivalent to multiplying byits reciprocal i.e. `b/a`. AS is apparent, reciprocal can be found just exchanging numerator and denminator.

As such `5/21-:15/7`

`hArr5/21xx7/15`

= `5/(3xx7)xx7/(3xx5)`

= `cancel5/(3xxcancel7)xxcancel7/(3xxcancel5)`

= `1/(3xx3)`

= `1/9`