Quadrilateral ABCD is dilated to form quadrilateral A'B'C'D'. Which statement is
true?

for finding the midpoint of any given 2 pair of points simply add the respective x coordinates with other x coordinate and the y coordinate with other y coordinate and divide them by 2

in your question it will be :

(3+1)/2 for the x coordinate of mid point i.e 2

[8+(-4)]/2 for the y coordinate of midpoint i.e 2

so coordinates of mid point of points (3,8) and (1,-4) will be (2,2)

y=mx+b is the final answer!   : )

step-by-step explanation: