Answer: Choice B) 
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Work Shown:

This shows why choice B is the answer.
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Explanation:
- In the second step, I multiplied top and bottom by

- This is so we can apply the difference of squares rule in step 3. The difference of squares rule is (x-y)(x+y) = x^2-y^2.
- In step 4, the square roots cancel out with the squaring operation. The two operations are inverses of one another, which is why they cancel.
So in general, if the denominator is
and you want to rationalize the denominator, then you should multiply top and bottom by
. The same applies in reverse as well.
This leads to the denominator becoming 
Keep in mind that
and 
The value of the expression C(6,3) is 20
<h3>How to evaluate the expression?</h3>
The expression is given as:
C(6, 3)
This means 6 combination 3.
And it can be written as:

Apply the combination formula

Evaluate the expression

Hence, the value of the expression C(6,3) is 20
Read more about combination at:
brainly.com/question/11732255
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Answer:350
Step-by-step explanation:
unknown is a
a% of 68=238
a/100 x 68=238
68a/100=238
Cross multiplying we get
68a=100x238
68a=23800
Divide both sides by 68
68a/68=23800/68
a=350
<span>If both signs are positive, the answer will be positive. Example: 14 - (-6) = 14 + 6 = 20.If both signs are negative, the answer will be negative. ... <span>If the signs are different subtract the smaller absolute value from the larger absolute value.</span></span>Is what I found