Pb is a line segment on a number line. it has endpoints at -2 and 12. what is the coordinate of its midpoint?

Well, first find the distance between the two numbers.
This can be done by adding the absolute values.

|12| + |-2| = 14.

mid = half

so what is half of 14? 7 is half of 14.

So, it is 7 less than the last point and 7 more than the first

-2 + 7 = 5
12 - 7 = 5

so, the midpoint is 5.
Hope this helps!