Answer:
Coordinates of M = (2, -1)
Length of AB = 10 units
Step-by-step explanation:
Coordinates of the midpoint (M) of the distance between A(2, 4) and B(2, -6)

Let 

Thus:



Length of AB:
Distance between A(2, 4) and B(2, -6):

Let,





Answer: It costs $5.52 to Sam to buy 12 stamps.
Step-by-step explanation:
Given: Sam paid $8.28 for 18 stamps.
Thus, the cost of 18 stamps = $8.28
Then the cost of 1 stamp=
Thus, the cost of 1 stamp=$0.46
With the same rate , the cost of 12 stamps=
Therefore, the cost of 12 stamps= $5.52
hence, it costs $5.52 to Sam to buy 12 stamps.