Question

PB has endpoints at -2 and 12. What is the coordinate of its midpoint?

Answer 1

I assume this is a horizontal or vertical line.
12-(-2)=14
14/2=7
12-7=5

The midpoint coordinate is 5.

Answer 2

$midpoint\ M_{PB}=\frac{P+B}{2}\\=======================\\P=-2;\ B=12\\\\M_{PB}=\frac{-2+12}{2}=\frac{10}{2}=5$