Jerry had some action figures on a shelf in his room. Later he added w more action figures to the shelf. If there are a total of x action figures on his shelf now How many action figures did he have initially on the shelf?
Let's say that Jerry had y action figures on the shelf initially. 

Then, after he added w more action figures, he would have y + w action figures on the shelf. 

However, we are told that there are x action figures on the shelf now. 

Therefore, we can set up the equation: 

y + w = x 

We can solve for y: 

y = x - w 

Therefore, Jerry had x - w action figures on the shelf initially.