Loop in two lists

I have these lists:

list1 = [3, 5, 2, 1, 9]
 list2 = [6, 9, 1, 2, 4]
 list3 = []
 list4 = []
 

and I want to pass these formula:

x = a/b
 y = 1/b
 

in which a is every value in list1 and b is every value in list2 and append the result of calculations into two empty lists - list3 and list4.

This is what I have but it's a disaster haha :(

u = 0
 while u<len(list1):
     for a in list1:
         for b in list2:
             x = a/b
             y = 1/b
             u+=1
             list3.append(x,)
             list4.append(y,)
 

Anyone can help me with this?

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