Question 282396
let's look at some examples first and see what we notice.
if we divide 20 by 5 we get 4
20/5=4 but 20 *1/5 also equals 4
so dividing by a number is the same as if we multiply by the reciprocal 
so if we divide by 1/5 we can also multiply by 5
if we divide by 5 we can multiply by 1/5

2/4 divided by 1/5 is the same as multiplying by 5
2/4*5=10/4
BTW 2/4 -1/2
so 1/2*5=10/4=2.5 or 2 1/2