Answer:
n = 7.5
Step-by-step explanation: Each side was multiplied by 3 to get the red triangle. So multiply 2.5 x 3 and it equals 7.5 which is n
You can see that 5 went to 15, and 5.5 went to 16.5. The only way to get there was to multiple each side by 3.
5x3=15
5.5x3=16.5
2.5x3=7.5