CPhill

If 4 people can do 1/2 the job in 2hr, 30 min [ 150 min], then it must take them 300 min to do the whole job.

And  we can use the "see- saw" principle, here.

4 * 300  = 10 * (time to do the same job)  ....    divide both sides by 10

4*300/ 10   = 120 minutes to do the whole job  for a crew of 10 people

Then, 1/3 of the job will take a crew of 10 people  40 minutes to complete

..............

sqrt (-2) =  sqrt(2) i

We could use the "formula,"  but we don't really have to.......

Subtract the y coordinates in any order   →  5/2 - 3/2   = 2/2  = 1

Subtract the x coordinates in the same order  →   11/4 - 3/4   = 8/4  = 2

Put the first result over the second  =   1 / 2     .......this is the slope......

Percent increase  =

 ([New Value - Old Value] / Old Value   x 100) %

Percent Decrease  =

 ([Old Value -  New Value] / Old Value   x 100) %

.000415E-3

This means :

.000415 x 10^-3   =

4.15 x 10^-4 x 10^-3 =

4.15 x 10^-7

Fill up the 5kg pot and pour the contents into the 3kg pot

Pour out the contents of the 3kg pot......the 5 kg  pot has 2kg remaining in it....pour these into the 3 kg pot.....the 3 kg pot now contains 2 kg

Fill up the 5kg pot.....pour 1 kg into the 3 kg pot

The 5 kg pot now contains exactly 4 kg

sqrt (1/7)   is irrational

But...if you're asking this:

sqrt(1)  / 7    = 1/7   and this is rational

0 / 0   is known as an "indeterminate form"

The reason why is that any real number times the denominator will return the numerator to us......

n^2 + 1000n - 200000  = 0

This will not factor

WolframAlpha  gives the solutions as :

-500 - 300sqrt(5)       and   -500 + 300sqrt(5)