Final answer:
The perimeter of the triangle can be found by combining like terms of the side lengths (5m-2n), (7m+10p), and (8p-9n), resulting in the expression 12m + 18p - 11n centimeters.
Step-by-step explanation:
To find the perimeter of a triangle with side lengths (5m-2n) centimeters, (7m+10p) centimeters, and (8p-9n) centimeters, you combine the like terms. The perimeter is the sum of all three side lengths, so you simply add these three expressions together:
(5m-2n) + (7m+10p) + (8p-9n)
Combine the terms that contain the same variables:
- For 'm': 5m + 7m = 12m
- For 'p': 10p + 8p = 18p
- For 'n': -2n - 9n = -11n
Now, combine these results to get the expression for the perimeter:
Perimeter = 12m + 18p - 11n
This expression represents the triangle's perimeter in centimeters.