Nadeen is at an arcade. she started out with 18 tokens, and each game costs 3 tokens to play. suppose x is the number of games nadeen has already played.

The expression describe the number of tokens Nadeen has left.

Step-by-step explanation:

Consider the provided information

Nadeen is at an arcade. She started with 18 tokens. Each game costs 3 tokens.

The cost of each game is 3 tokens

Suppose x is the number of games played by Nadeen

Thus, the cost of x games is 3x tokens

it is given that Nadeen started with 18 tokens.

So, token left =

Therefore, the expressions can be used to describe the number of tokens Nadeen has left.

he used the algebra tiles correctly.

step-by-step explanation:

given : 3x(2x-1)

solution :

since he used algebra tiles .

armando's solution is the same in the solution shown in figure

as he distributed 2x into x and x and wrote them vertically

and also write   -1 vertically

and 3x into x and x and x and wrote it horizontally

performing the multiplication in the algebra tiles we get

and solving the given expression :

3x(2x-1)

since solving the expression using tiles   and solving the expression algebraically we get the same answer

thus   we can choose the first statement as the answer to this problem which is "he used the algebra tiles correctly".