It’s doesn’t satisfy the equation
The correct answer for the given problem above would be the fourth triangle. So here is the given solution: Since Triangle 1 is already given with a measurement of 50 inches, and 80% of 50 inches if 40. Triangle 2 then is 40 inches. 80% of 40 is 32, so triangle 3 is 32 inches, and then 80% of 32 is 25.6 inches so triangle 4 is 25.6 inches. Therefore, the triangle that will first have a side length of less than 29 inches is triangle 4.
Answer: (D) 
Explanation:

Just a note on writing down these expressions: I recommend using parentheses whenever you can to avoid misinterpretation. An expression 1/x-1/y / 1/x+1/y could be interpreted by someone as 1/x-(1/y / 1/x)+1/y, which is a different thing.
Answer:
this is the answer
Step-by-step explanation: