How much higher is 500 m than -400 m?

900 meters

Step-by-step explanation:

Think of it like this. Make a number line. Start with the positive side, from zero to 100 to 200 all the way up to 500. Then go back to zero, and count by negative 100 until you get to negative 400. Then start from -400 and count by 100s till the 500 mark. You'll get 900. (don't forget to label meters!)

translate k to n and reflect across the line containing jk.