Question

solve for x: 8 is to 64 as 2 is to x

Answer 1

either 4 or 16

Answer 2

really not enough info to solve this uniquely

8 is to 64 could be 8^2 or 8*8 as 2 simple relationships or 8+56 (there are many other options)

So
if we take the relationship ^2 tehn the answer is 4
if we take the relationship is *8 then the answer is 16
If we take the relationship as +56 tehn the answer is 58

A very poorly defined question.