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) what is sebastains error

Answer: He took 9 instead of -9 and -7 instead of only 7.Step-by-step explanation:We know that in integers , we use negative(-) sign to represent the "down" or loss and positive(+) sign to represent "up" or "gain" in any amount.Since , we have given that , Sebastian was in a hotel lobby and took the elevator up 7 floors to his room.This will represent by 7 not -7 in integers.Then he took the elevator down 9 floors to the parking garage.This will represent by -9 not only 9 in integers.Then , the movement of Sebastian is given by : +7+(-9)Therefore, the Sebastian's error is : He took 9 instead of -9 and -7 instead of only 7.