To find the distance between any numbers on the number line, subtract the smaller number from the bigger number.
73 - (-54) = x
Since subtracting negative numbers is the same as adding positive numbers ('two dashes (-) makes a plus sign' might be easier to remember) we can write:
73 + 54 = x
Solve
73 + 54 = 127
The answer is D
Hopefully this helps! If you have anymore questions or don't understand, feel free to DM me!! :)