Answer:
ummmmm i think apple?
Explanation:
because if 4 equals green and you put the square root of branch in there you will get branch×apple tree+water=apple my bad its green apple
i did it wrong i just redid the question and found the right answer. so if you put branch×square root of 9 apples+apple tree=9 apples right? well yes but if you add branch+square root of 4 more apples you will get in total 13 apples.