Represent each of her employee's explanations with an algebraic expression that describes how many new tiles must be added to
an nxn square to build the next design.

Wilma
I must add 3 tiles to each of the four sides of the white
square, which is 4*3 tiles. Then I must add 1 tile at each corner. So the number of additional tiles added to the Design 2 square floor design is 4*3 + 4. Write an expression to represent this.

Expression: