They hiked the same distance because they were hiking at the same rate.
Answer is A m^7/n^2 -----------------
Blue triangle: perimeter is 4x+2+7x+7+5x-4, or, after simplification,
16x + 5
Red triangle: perim. is 2x-5+x+7+x+3 (and so on).
Add numbers with the same amount of variables
-x^2 + (-7x^2) = -8x^2
– 28x (+ 14x )= -14x
7 (+ 8) = 15
-18x² - 14x + 15 is your answer
hope this helps