You and three of your friends buy tickets for a concert so that you sit together in the same row. Write an expression using factorials that could be used to find the probability that you will get the seat on the far left.

Step-by-step explanation:

Given

Required

Probability that you seat on the far left

First, we calculate the total possible seat arrangements.

This is calculated using:

Next, the possible seat arrangements if you seat at the far left.

This implies that you can only seat 1 spot while your friends (3) can seat on any of the remaining 3 seats.

i.e.

The number of arrangement is:

The required probability is:

Simplify

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".

i believe the correct answer is b.