Answer:
21
Step-by-step explanation:
Work=speed times time (my equation to help me figure it out)
ok, 10 men take 84 days to complete a job
therefor, each man completes 1/10 of the job in 84 days
each man does 1/840 of the job per 1 day
so, if we had 5 more, or 15 men
15 times 1/840 times xdays=1 job complete
15/840 times xdays=1job
times both sides by 840/15
xdays=840/15
xdays=56
56 days it would take
Find coordinate of points
Point P coordinates are (x,y) =
x is same that point L, y = 0 .
Then coordinates for P = (a,0)
Point M coordinates
x is same that point N, x=b
y is same that point L , y=c
Then coordinates for M = (b,c)

First, you need to find where you can move the decimal point to so that there is only one non-zero digit to the left of it.
Move the decimal point, and that is the first part done.
Add "
".
For the last part - the power, you need to find how many decimal places you moved the decimal point. In this case, we moved it to the right 2 places, so the power is
.
If, for example, we had moved the decimal point three places to the left, the power would be
.