Question

Sebastian was in a hotel lobby and took the elevator up 7 floors to his room. Then he took the elevator down 9 floors to the parking garage. He described his movement with the expression below.9+(−7) NOTE: There is a check answer button in the bottom right corner. Click this to check your answer before moving on to the next question. It will not tell you the correct answer, but it will tell you if the answer you selected is correct. You can use this feature once per question.(1 point)ResponsesSebastian should have started at zero before adding –7.Sebastian should have started at zero before adding –7.Sebastian should have used –9 and 7.Sebastian should have used –9 and 7.Sebastian should have used 0 and –9.Sebastian should have used 0 and –9.Sebastian should have switched the two addends and written −7+9.

Answer 1

To analyze Sebastian's movement correctly, let's break it down step-by-step:

1. He starts at the hotel lobby (which we can define as a starting point, say 0).
2. He moves up 7 floors to his room. This can be represented as +7.
3. Then he moves down 9 floors to the parking garage. This is represented as -9.

To calculate his final position, you would start from his initial position (0), add 7 for the upward movement, and then subtract 9 for the downward movement. The expression can thus be written as:

0 + 7 + (-9) or simply 7 + (-9) or 7 - 9.

In the expression you provided, 9 + (-7), does not accurately reflect the situation as it incorrectly swaps the floors moved down.

So, the correct option to choose from your responses would be:

Sebastian should have used –9 and 7.

This reflects the correct movements of moving up 7 floors and then down 9 floors.