Answer: D. 
Step-by-step explanation:
Using exponent rules an exponent to the power of a number will multiply by each other.
So the -4 and -9 will multiply.
The 6 in the numerator will now have a positive exponent of 36.
Now we can divide and when we do so the exponents will subtract from each other.
So 36 - 6 = 30
And the base of 6 does not change.
The simplified form is
1/3 is the answer. Hope this helps
The formula to calculate work done is -
Work done ( in joule, J) = Force (in Newton) X Distance (in meters)
So, we will use the formula to calculate work done,
Here, force is given as = 7 newtons
Distance is given as = 3 meters
So, work done will be -
Work done ( in joule, J) = 7 Newtons X 3 Meters
<u>Work done ( in joule, J) = 21 J (in joule)</u>
This one is best done by elimination:
We need to start 4 meters away, so B is clearly wrong.
We first move towards Mr. Wilson (i.e. distance is decreasing) so A is wrong.
Our speed is faster on the way back, so the two sloped section must have differing slopes, so D is wrong.
(D also doesn't start at 4, it's wrong for two reasons.)
Only C is left.
We can check each part to make sure. First we start at 4m, then move away, then stay still (zero slope) for three seconds, then move back faster (higher slope). All parts check out ok.
