Answer:
see explanation
Step-by-step explanation:
The diagonals of a rectangle are congruent, thus
MP = LN , substitute values
9x - 9 = 7x + 9 ( subtract 7x from both sides )
2x - 9 = 9 ( add 9 to both sides )
2x = 18 ( divide both sides by 2 )
x = 9
LN = 7x + 9 = (7 × 9) + 9 = 63 + 9 = 72
MP = 9x - 9 = (9 × 9) - 9 = 81 - 9 = 72