I want to say A but im not sure
You could do all of the work with the multiplying, but what I think it wants you to see is that you can divide like numbers by subtracting exponents.
so if we did that we would get 
this in turn would give us 4 x -9 x -5 = 180
divide 63 by9
63 / 9 = 7
each piece is 7 meters long
Answer:
3*57=171
Step-by-step explanation: