Write the following as an algebraic expression. Then simplify.
The perimeter of the square with side length y.

4y

Step-by-step explanation:

The perimeter means the sum of all sides. A square has four equal sides, and we know each side is "y".

y + y + y + y

Then simplify that expression. Collect like terms, which are numbers with the same variables. All of them are "y", so combine them by adding.

y + y + y + y

4y                Simplified expression

Remember an expression means there is no equal sign.

P = 4y         is an incorrect answer.

That would be an equation.