X represents the length of a deck. There are three parts to this equations. The 1. width, 2. the length, and 3. the 5 feet shorter. Using the key words, y = the width of a deck (uses the term is which means =) So that takes the width part out of the equation. Then, 5 feet shorter means -5 than a number. That takes away the 5 feet shorter part of the equation. That leaves x to equal the length of the deck.
