Answer: 0.1x - 16 (c)
Explanation: The perimeter is the sum of all three sides of the triangle. Since the three side are 0.5x + 9, 3x, and (-3.4x) - 25, the sum is as follows:
0.5x + 9 + 3x + (-3.4x) - 25 = 0.1x - 16
