He then went to see the oranges being harvested. He found out that they harvest w sacks per day. How many days will it take to harvest x sacks of oranges?
First, we need to find out how many sacks of oranges are being harvested per day. We know that w sacks are being harvested per day. 

Now, we need to find out how many days it will take to harvest x sacks of oranges. To do this, we need to divide the number of sacks of oranges by the number of sacks being harvested per day. We know that x sacks of oranges need to be harvested, so it will take x/w days to harvest them. 

Therefore, the answer (symbolic expression) is: 

x/w