Answer:
(a) 3, 5 and 6
Step-by-step explanation:
In the experiment, 43 are to be given a gel that contains the tooth-whitening chemicals while the remaining 42 are to be given a placebo. Therefore, a placebo is used.
The 43 that will receive the gel are to be selected randomly.
After the experiment, the whiteness of the two groups will be compared to see the effect of the gel.
Therefore for the experiment to be completely random, 3, 5, and 6 apply.
(b)
For the experiment to be double-blind, the researchers who will evaluate the whiteness and interact with the subjects, and the subjects would not know which subjects received either the whitening gel or the placebo.
<span>(2n + 2)(2n – 2)
= (2n)^2 -2^2
= 4n^2 - 4
hope it helps</span>
Answer:
1. 1/4+1/4=2/4=1/2
2. Yes
3. i don't know
4. Yes
Step-by-step explanation:
1. 1+1=2 therefore you get 2/4 or 1/2
2. 2/3 is the reduced form of 4/6
3. i honestly dont know
4. 3/4 is the reduced form of 9/12
Answer:
B
Step-by-step explanation:
So remember that a quarter of a circle is 90 degrees, a half of a circle is 180 degrees, and a whole circle is 360 degrees.
Looking at the image shown, it must be half a circle, whihc is 180 degrees. The image tells us that the 1st angle is 7 degrees. Now, we must find the 2nd angle.
Heres what we know however:
angle 1 + angle 2 = 180 degrees.
How do we know this?
Well, there are only 2 angles in this 180 degrees. We know that the first one is 7 degrees.
Lets input that into our nice lil equation to get an answer:
7 degrees+angle 2 = 180 degrees
Now lets solve.
Subtract 7 on both sides, and your left with:
angle 2 = 173 degrees.
So the answer must be:
<u>173 degrees</u>
Hope this helps! ;)
