On a biology test, a student got 25 questions correct but did not pass. on a second attempt, the student got 36 questions correc
1 answer:
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Answer:
11.51
Step-by-step explanation:
In general, a calculator is required to evaluate the irrational sum ...
π + √70
<h3>Calculator result</h3>The result from a readily-available online calculator is shown in the attachment.
π + √70 ≈ 11.51
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<em>Additional comment</em>
You have probably memorized pi to several digits: 3.1416. To obtain the required estimate means you need to approximate √70 to about the same level of precision.
For a number n = a² +b, the square root can be approximated by the continued fraction ...
√n ≈ a +b/(2a +b/(2a +...))
Effectively, the root (r) can be iterated from the recursive formula ...
r' = a +b/(a +r)
For √70, we have 70 = 8² +6 ⇒ a=8, b=6
If the initial approximation of the root is r0≈a=8, then a couple of iterations gives ...
r1 = 8 + 6/(8 +r0) = 8 + 6/(8 +8) = 8 3/8
r2 = 8 + 6/(8 +r1) = 8 +6/(8 +8 3/8) = 8 48/131
This has sufficient accuracy for the purpose. The decimal equivalent of the sum then becomes ...
3.1416 +8.3664 = 11.5080 ≈ 11.51
Answer:
JK got 30 answers correct on a 50 item test.
Step-by-step explanation:
It is given that:
Total items on test = T = 50
Fraction of total items that were answered correctly = 3/5
We simply have to multiply the total number of questions by the fraction of correct answers.
So,
The correct answered number of items are:
Hence,
JK got 30 answers correct on a 50 item test.
<span><u><em>The correct answer is: </em></u>
C) his solution for x is correct, but in order for 6 to be an extraneous solution, one denominator has to result in 0 when 6 is substituted for x.
<u><em>Explanation: </em></u>
<span><u>To solve this rational equation, we cross multiply: </u>
8*(x-4)=2*(x+2).
<u>Using the distributive property, we have </u>
8*x-8*4=2*x+2*2;
8x-32=2x+4.
<u>Subtract 2x from each side: </u>
8x-32-2x=2x+4-2x;
6x-32=4.
<u>Add 32 to each side: </u>
6x-32+32=4+32;
6x=36.
<u>Divide both sides by 6:</u>
</span></span>
<span><span>=</span></span>
<span><span>;
x=6.
<u>Extraneous solutions</u> are solutions that come about in the problem but are not valid solutions to the problem; the only values of x that would give this sort of answer are -2 and 4, since these are the two values that would make one of the denominators 0 (we cannot divide by 0).</span></span>
C) his solution for x is correct, but in order for 6 to be an extraneous solution, one denominator has to result in 0 when 6 is substituted for x.
<u><em>Explanation: </em></u>
<span><u>To solve this rational equation, we cross multiply: </u>
8*(x-4)=2*(x+2).
<u>Using the distributive property, we have </u>
8*x-8*4=2*x+2*2;
8x-32=2x+4.
<u>Subtract 2x from each side: </u>
8x-32-2x=2x+4-2x;
6x-32=4.
<u>Add 32 to each side: </u>
6x-32+32=4+32;
6x=36.
<u>Divide both sides by 6:</u>
</span></span>
x=6.
<u>Extraneous solutions</u> are solutions that come about in the problem but are not valid solutions to the problem; the only values of x that would give this sort of answer are -2 and 4, since these are the two values that would make one of the denominators 0 (we cannot divide by 0).</span></span>