Answer:
b - a
Explanation:
Given M and N are midpoints, let's find the coordinates of the midpoints first. Then we can use that information to find the length
The midpoint formula is
( (x1 + x2)/2, (y1 + y2) / 2 )
So M = ( (2a + 2c)/2, (0 + 2d)/2 ) = (a + c, d)
And N = ( (2c + 2b)/2, (2d + 0)/2 ) = (c + b, d)
Because the y-coordinates are the same (d), the distance from M to N is,
final x-coordinate minus initial x-coordinate
x-coordinate of N minus x-coordinate of M
(c + b) - (a + c)
Distribute the negative and remove the parentheses
c + b - a - c
Group the cs together
c - c + b - a
Cancel out the cs
b - a