Answer:
4x-4y
Step-by-step explanation:
4x+11y-15y
Combine like terms
4x-4y
Here, You need to apply "Proportionality Theorem"
According to this theorem, the ratio of components of a leg would be equal to the ratio of corresponding components of another leg.
In mathematical form,
AB/BD = AC/CD
Substitute their values,
36/24 = x/18
2/3 = x/18
x = 18*3 / 2
x = 54 / 2
x = 27
In short, Your Answer would be 27
Hope this helps!
Answer:
The complete question is:
At a university, 13% of students smoke.
a) Calculate the expected number of smokers in a random sample of 100 students from this university:
b) The university gym opens at 9 am on Saturday mornings. One Saturday morning at 8:55 am there are 27 students outside the gym waiting for it to open. Should you use the same approach from part (a) to calculate the expected number of smokers among these 27 students?
Part a is easy, because is a random sample, we can expect that just 13% of these 100 students to be smokers, and 13% of 100 is 13, so we can expect 13 of those 100 students to be smokers.
b) This time we do not have a random sample, our sample is a sample of 15 students who go to the gym in the early morning, so our sample is biased. (And we do not know if this bias is related to smoking or not, and how that relationship is), so we can't use the same approach that we used in the previous part.
Answer:
The chemist needs to add 400mL of 40% solution.
Step-by-step explanation:
The equation
gives the percent concentration 
of the final mixture, when 
mL of the 40% solution are added.
Now we are asked, how many milliliters of the 40% solution should the chemist add to get final percent concentration 
; this is just a matter of solving the equation
and we solve it the following way:
Thus, the chemist needs 400mL of 40% solution to get 30% concentration of the final mixture.
<span>2 x - 6 = 20, where x is the temperature in degrees Farhenheit 6 hours ago. 2 x = 20 + 6, 2 x = 26, x = 26 : 2, x = 13 degrees F. We can prove it: 13 * 2 - 6 = 26 - 6 = 20 degrees F ( the current temperature ) Answer: The temperature 6 hours ago was 13 degrees F.Hope this helps. Let me know if you need additional help!</span><span />
