There were w dollars in Olivia's wallet. She collected x more dollars from an atm. After she visited a supermarket there were x dollars left. How much more money did she collect at the atm than she spent at the supermarket?

Olivia's wallet had w dollars in it. 

She visited an ATM and collected x more dollars. 

This means that after she visited the ATM, she had w + x dollars. 

She then went to the supermarket, and spent some money. 

After she spent the money, she had x dollars left. 

This means that she spent w + x - x = w dollars at the supermarket. 

Now we can set up an equation. 

w + x - (w + x - x) = x 

w + x - w - x + x = x 

2x = x 

x = 0 

This means that Olivia spent the same amount of money at the supermarket as she collected from the ATM.