How do I find X when I'm using a balance with pictures?

Question

There is a balance. On the left side there are 4 oranges and 2 boxes. On the right side there are 10 boxes.  The question is : " One orange is the same as ------ X's."  It doesn't give me the value of X. How do I solve it? I know that the correct answer is 4, but I have no idea why.

Answer 1

4 oranges + 2 boxes = 10 boxes,

4 oranges = 8 boxes,

1 orange = 2 boxes.