I need Help pleaseeee

Answer:
AB = 3.5 cm
Step-by-step explanation:
The error was the 2 numbers being switched. Instead of 1 - 4.5, the correct calculation should be 4.5 - 1 which equals 3.5
Answer:
The correct number is +3.5
Step-by-step explanation:
AB is the distance from A to B. It is headed to the right, as the numbers increase. So the calculation should be (Final - Initial), or (4.5 - 1) = 3.5