Answer:
42.9
Explanation:
The triangles are similar, so corresponding side lengths are proportional.
Consider the left side of the figure:
MA +AN = MN
MA = MN -AN = 67.2 -32 = 35.2
Now, we can write the proportion ...
MB/MP = MA/MN
x/81.9 = 35.2/67.2 . . . . . .fill in the known values
x = 81.9(35.2/67.2) . . . . . multiply by 81.9
x = 42.9