To represent the distance traveled by Lizard D in relation to Lizard A, we can define the distance traveled by Lizard D as \( y \). According to the information given, Lizard D traveled \( 31 \) feet less than Lizard A, whose distance is represented by \( x \).
We can express this as:
\[ y = x - 31 \]
This is the equivalent equation that shows another way to represent the distance that Lizard D traveled.