SAT Math HELP Cont'd

Test Preparation SAT Preparation
1

<p>Please help and expain if you can.</p>

<ol>
<li>Which of the following lists of three expressions denotes three consecutive odd integers for every integer n?</li>
</ol>

<p>A. n,3n,5n
B. n+1, n+3, n+5
C. 2n+1, 2n+3, 2n+5
D. n, n+1, n+2
E. 2n+1, 2n+2, 2n+3</p>

<p>7.If x =16 is a sollution to the equation 9x-k=130, where k is a constant, what is the value of k?
(Isnt k just 14? or is there more to it than pluggin in x?)</p>

<ol>
<li>If a circle with center at the origin passes through the point (0,5), through which of the following points does it also pass?</li>
</ol>

<p>A. (2, √21) B. (4,5) C. (5, √21) D. (5,5) E. (5,12)</p>

<ol>
<li><p>In the figure the Circle has a radius of 10 and its center is the origin. Which of the following points lie outside the circle?
A. (-7,-8) B. (-7,7) C(8,-6) D(8,5) E(9,4)
(I assumed it was either A or C...)</p></li>
<li><p>Triangle ABC and ABD share side AB. Triangle ABC has area Q and triangle ABD has area R. If AD is longer than AC and BD is longer than BC, which of the following could be true?</p></li>
</ol>

<p>I. R>Q
II. R=Q
III. R<Q</p>

<p>A. I only B. III only C. I and II only D. I and III only E. I, II, and III</p>

2

<ol>
<li><p>C. Just plug in numbers for this one. If any integer you plug in yields an even number, cross it off.</p></li>
<li><ol>
<li>Just plug in x = 16 and solve for k.</li>
</ol></li>
<li><p>I think it’s A. The radius of the circle is 5 and it’s center is at (0,0), meaning the circle has the equation of x^2 + y^2 = 25 (x^2 + y^2 = radius ^2).</p></li>
</ol>

<p>I plugged in 2 for x and root 21 for y and solved, (4 + 21 = 25).</p>

<ol>
<li>You can use the same method from 8 here. x^2 + y^2 = r^2</li>
</ol>

<p>x^2 + y^2 = 100</p>

<p>Any choice whose x and y (when plugged into the equation above) exceed 100 should lie outside of the circle.</p>

<p>Since A = 114 (7^2 + 8^2 > 100) it is the right answer.</p>

<p>I’ll do #10 if I have time later.</p>

3

<p>Okay thank you!</p>

4

<p>6)
We can eliminate A,B,and D - since the first term doesn’t work for all values of N.
So stuck between C and E - test out the second term.
Since the first term is odd(required by question), and both C and E have the same term, we can just use a random odd number. 5.</p>

<p>2n+2 = 12
2n + 3 = 13</p>

<p>Therefore C is correct.</p>

<p>7) answer should be 14. I don’t think you need explanation why.</p>

<p>8) You know that the radius is 5, so the the distance of between the center and one of the answer choices must be 5. </p>

<p>Since you know that the origin is 0,0. The coordinates of the point thats on the line should satisfy this equation, x^2 + y^2 = 25 (this is a simplification of the distance formula). Do a quick scan of the answer choices, immediately eliminate anything that is obviously greater than 25, like B,C,D,E. Therefore we are left with A.</p>

<p>A is the answer, and you can double check with distance forumula to be sure.</p>

<p>9) Similar idea as above, the point must be greater than 10. </p>

<p>So, x^2 + y^2 > 100</p>

<p>Do a quick check, see which ones satisfy the equations, keeping a look out for especially large numbers coupled. </p>

<p>Try A, 49 + 64 > 100 is true, so A is the answer.</p>

<p>C, 64 + 36 = 100, does not satisfy the equation.</p>

<p>10) This is basically, they give you two triangles, one has two sides larger than the other and both share one side. In my head, I just drew two isosceles triangles within each other, place point C right under point D - this will give you a representation of their areas. </p>

<p>As you can see, only R>Q can work, following all the restrictions. Therefore A. I only</p>