Answer:
15
See two explanations below.
Step-by-step explanation:
The correct mathematical way to find the distance between two points on the number line, is to take the absolute value of the difference of the coordinates (numbers) of those points.
The distance between the points with coordinates a and b is |a - b|. If you do the subtraction in the other order, |b - a|, you get the same result.
Distance between -9 and 6 is:
|-9 - 6| = |-15| = 15
If you subtracted in the other order, you'd get the same result:
|6 - (-9)| = |6 + 9| = 15
As you can see, the distance is 15.
Now let's do it by just using logic and knowledge of the number line.
The point -9 is 9 units to the left of zero.
The point 6 is 6 units to the right of zero.
What is the distance from -9 to 6?
Start at -9 (9 units left of zero) and start moving toward 6. First you get to zero. It takes 9 units to go from -9 to 0. Now go from 0 to 6. It takes 6 units to go from zero to 6. Add the two distances, 9 + 6, and you get 15.
The distance from -9 to 6 on the number line is 15.
