How do you divide multiply fraction?

Answer 1

You do it the obvious way.

Take p, q in Q, the rationals

By definition, we can write p = m/n and q = r/s where m, r are integers, n and s are natural.

we define pq (p times q) = (mr)/(ns)

p/q = pq^-1 where q^-1 denotes q's multiplicative inverse s/r

Remark: you cannot divide by 0 here because

1) 0 have no multiplicative inverse

2) if r = 0. s/r is undefined.