Geometry question involving midpoints and coordinates

The question says: "The midpoint of segment AB is M(7,5). The coordinates of point A are (4,1). Find the coordinates of point B. Explain." Thanks!

consider a line AB with mid pt D as (7,5).
consider the pt B as (x,y) to be found.
so using mid pt formula of a line segment,
7 = (4+x) / 2
so x = 10
similarly,
5 = (1+y) / 2
so y = 9
so the required pt B is (10,9).....

Midpoint means the point is exactly in the middle of the line.

Graph it out. Graph paper is your friend! Graph point A and point M. Connect the points with a ruler, and then measure the distance between them. Line your ruler up with the line, and measure the same distance from point M. Where you end is point B!!!