Yes, there was a mistake in applying the distributive property. If you have to perform

you have to multiply both terms in the parenthesis by 3, not just the first one.
So, the correct expansion would be

Answer:8.6
Step-by-step explanation:
The easiest way to do this is for you to subtract all the sides from the total perimeter since the perimeter is all of the sides added and your remainder is your answer
Hope this helps
Answer:
80.8
Step-by-step explanation: 0.7x4x6=16.8
16.8+8 to the 2nd power= 80.8