===============================================
Explanation:
The midpoint formula is [tex](x_m, y_m) = \left(\frac{x_1+x_2}{2},\frac{y_1+y_2}{2}\right)[/tex]
This basically says to add the corresponding coordinates and divide by 2.
The given points (2,5) and (4,-7) have x coordinates of 2 and 4. They add to 2+4 = 6, and then that result cuts in half to 6/2 = 3. The x coordinate of the midpoint is 3.
The y coordinate of the midpoint is y = -1 since adding the y coordinates of the given points leads to 5+(-7) = -2 which cuts in half to -1.
So overall the midpoint is located at (3, -1)