Answer:
Because the kind of compounfds that you try to determine using paper chromatography (organic compounds) are usually not soluble in water. Furthermore, water could react chemically with some of this compounds, because it's a very reactive molecule. You need organic solvents that are mostly inert.
Answer:

Step-by-step explanation:
We are given the following in the question:
Quantity, q
Selling price in dollars per yard, p

Total revenue earned =

f(20)=13000
This means that 13000 yards of fabric is sold when the selling price is 20 dollars per yard.
f′(20)=−550
This means that increasing the selling price by 1 dollar per yards there is a decrease in fabric sales by 550.
We have to find R'(20)
Differentiating the above expression, we have,

Putting the values, we get,

Step-by-step explanation:
You have 5 digits.Youdonot say if duplication is allowed. I will assume not
For the first digit you have 5 choices. One of the 5 digits is gone.
You now have 4 digits to choose from. You pick one. Now you have but 3 left.
The total answer if 5*4*3*2*1 = 120
Answer:
D
Step-by-step explanation:
It turns out from similar triangles, that 7/BD = BD / 18. Use triangles ABD and BDC to show this relationship. Solving this equation will give you BD
BD^2 = 7*18
BD^2 = 126 Just leave it in this form. Do your rounding at the end.
Because triangle BDC is a right angle triangle, use the Pythagorean Theorem to solve for m
m^2 = BD^2 + 7^2
m^2 = 126 + 49
m^2 = 175 Take the square root of both sides.
sqrt(m^2) = sqrt(175)
m = 13.22
so the answer is D
What is the time it takes Sanjay to complete the puzzle? 6 hours
What is the time it takes Felipe to complete the puzzle? 8 hours
We can use the general formula of rate and time to solve this problem. Generally we have,
<em><u>Rate * Time = Work/Job</u></em>
<em>** where Work/Job for this problem is 1 since they are doing 1 work, which is solving a puzzle</em>
- <u>Finding rate of Sanjay:</u>

- <u>Finding rate of Felipe:</u>

Working together, their rate is the sum,
Total Rate =
.
Using the general formula again, we can find the time it will take to solve the puzzle when both works together.
hours
Rounding the answer, we have 3.4 hours.
ANSWER: 3.4 hours