21/2 ÷ 1 5/8 =
two and a half divided by one and five eights

So first of all we can't start by changing them both into improper fractions

So it would be:
5/2 divided by 13/8
From there you would do 5/2 * 8/13 which could convert to
5/1 * 4/13 which would be 20/13

1 7/13. First, you put them into improper fractions and it would be 5/2 ÷ 13/4. then you need to turn it into a multiplication problem so it would come out as 5/2 ÷ 4/13. then you just multiply it out.