David did w more push-ups than Zachary in gym class today. If David did x push-ups How many push-ups did Zachary and David do altogether?
First, we know that David did more push-ups than Zachary. This means that the number of push-ups David did, x, is greater than the number of push-ups Zachary did. 

We also know that the total number of push-ups done by both David and Zachary is w. 

Now, we can set up an equation to solve for w. 

x + y = w 

We know that y is less than x, so we can say that y is less than w. 

Now we have two equations: 

x + y = w 
y < w 

We can solve for w by finding the intersection of these two equations. 

The intersection of these two equations is w = x. 

This means that the total number of push-ups done by both David and Zachary is equal to the number of push-ups that David did.