Jesse's room is 19 feet wide and 20 feet long. How much longer is her room than it is wide?
Let's denote the length of the room by $l$ and the width of the room by $w$. 

We are told that $l=20$ feet and $w=19$ feet. 

We want to find out how much longer the room is than it is wide. In other words, we want to find $l-w$. 

We have $l=20$ feet and $w=19$ feet. 

Therefore, $l-w=20-19=1$ foot.