three more pancakes than his brother ate

b + 3

Three more pancakes then his brother ate

To find out how many pancakes his brother ate, we need more information.

To find out how many pancakes the person ate, you need to know how many pancakes his brother ate. Let's call the number of pancakes the brother ate "x".

If the person ate three more pancakes than his brother, you can simply add 3 to the brother's number of pancakes.

So, the number of pancakes the person ate can be expressed as "x + 3".