Answer:
y=1/6x+1 because the formula is written as y=mx+b
1 batch = 3 + 1+ 2
5 batches = 5( 3 + 1 + 2) [Answer A]
Perimeter is the outside of it and the perimeter is the inside of it, so I'm pretty sure you would have to do both but if u have to do one then I would go with area