Brandie lives on the twelfth floor of her apartment building. She walks down 2 flights to visit a friend, then up 3 flights to deliver a message to a neighbor. Which integer best represents the number of flights Brandie must walk to get back to her starting point? A). -12
B). -1
C). 5
D). 7

Option (B) is the correct answer.

Step-by-step explanation:

Let 'x' the starting point be

She walks down 2 flights to visit a friend.

so walking down means we need to add 2 units to the starting point x

Then he walks up 3 flights to deliver a message to a neighbor.

now subtracting 3 units from (x+2)

x = -1 means now he is UP to 1 point where he started his flight.

Thus, he needs to walk down 1 more flight to reach her starting point

Thus, -1 is the number of flights Brandie must walk to get back to her starting point.

Therefore, option (B) is the correct answer.