A’Leila is building a pen for her pet donkey. The pen is a rectangle with one side

To find the perimeter of a rectangular pen, we can use the formula for the perimeter \( P \) of a rectangle, which is given by:

\[ P = 2 \times (a + b) \]

where \( a \) is the length of one side and \( b \) is the length of the adjacent side.

Now, we can express the perimeter in two different ways:

1. First Expression: Using the formula directly, we can write: \[ P = 2a + 2b \]

2. Second Expression: We can factor out the 2 from the first expression: \[ P = 2(a + b) \]

So, the two different expressions for the perimeter of A’Leila's donkey pen are:

1. \( P = 2a + 2b \)
2. \( P = 2(a + b) \)