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
Answer:
b
Step-by-step explanation:
See the attached image.
First add 1/2 and 3/4 together by making 1/2, 2/4 then add 3/4 to get 5/4 or 1 1/4 then 10 - 1 1/4 is 8 3/4 which is the answer
I think its 55 meters but ry to check first