Answer:
D. 66 cm
Explanation:
You have parallelogram MNPR with diagonals that cross at E, and ME = 7x-30, and PE = 5x-12. You want to know the length of MP.
Diagonals
The diagonals of a parallelogram bisect each other this means point E is the midpoint of diagonal MP, and ...
ME = PE
7x -30 = 5x -12
2x = 18 . . . . . . . . . add 30-5x
x = 9
Then the length of the half-diagonal is ...
ME = 7x -30 = 7(9) -30 = 33
So, the full diagonal is ...
MP = 2·33 = 66 . . . . . cm