Hey there! :)
Answer:
C) 74 units.
Explanation:
MT is congruent to KT because the diagonals of a quadrilateral bisect each other. Therefore:
8y + 18 = 12y - 10
Subtract 8y from both sides:
18 = 4y - 10
Add 10 to both sides:
28 = 4y
Divide both sides by 4:
28/4 = 4y/4
y = 7 units. Plug this into the equation for MT:
8(7) + 18 = 74 units.