hello!
so I think this is how you do it, or I'm not reading it correctly aha,
if 4/5 is the same as ?/20, you would find out what you do to 5 to get to 20,
20÷5=4
that means whatever you do to the bottom you do to the top!
so 4×4=16!
16/20
I hope this helps ~~♡♡chyna