I need help with solving a few Math problems.

Test Preparation SAT Preparation
1

<p>Hello everyone. Care to explain a few problems to me?</p>

<p><a href="http://imgur.com/N96G5.png%5B/url%5D"&gt;http://imgur.com/N96G5.png&lt;/a&gt;&lt;/p>

<p>The answer for this was D.</p>

<p><a href="http://imgur.com/kNFca.png%5B/url%5D"&gt;http://imgur.com/kNFca.png&lt;/a&gt;&lt;/p>

<p>The answer for this was 75.</p>

<p><a href="http://imgur.com/5VvO0.png%5B/url%5D"&gt;http://imgur.com/5VvO0.png&lt;/a&gt;&lt;/p>

<p>The answer for this was 1600.</p>

<p>How does one get these answers?</p>

2

<p>For the first one, I thought it was C, but after another quick look, I know now that it is D. The point on the y-axis is (0,3), which suggests that there would be two values, one to the left and one to the right, for f(x) = 2. There would then be another value just before x = 6, making the answer D.</p>

<p>Okay, I got it. Define AC as a. Define CE as b. The perimeter of the triangle is x.</p>

<ol>
<li>a + b = 25</li>
<li>3a + 3b = x</li>
<li>25 - a = b *** SUBSTITUTION!</li>
<li>3a + 3(25 - a) = x</li>
<li>3a + 75 - 3a = x</li>
<li>75 = x</li>
</ol>

<p>For the third one, use algebra. Make the number you’re looking for equal x.</p>

<ol>
<li>The square root of x is equal to x / 40.</li>
<li>Square both sides. x = (x/40)^2</li>
<li>Expand the right side: x/40 * x/40 = x^2/1600. It is still equal to x.</li>
<li>Multiply both sides by 1600. 1600x = x^2</li>
<li>Divide both sides by x. 1600 = x</li>
</ol>

3

<p>For the first problem simply put notch marks on the x/y axis and put a horizontal line across where y=2. It will intersect the function in three places.</p>

<ol>
<li>Any way you break it down the answer is 75.
You can cut the segment in half so the equation would be as followed:</li>
</ol>

<p>12.5(3)+12.5(3)</p>

<p>Or break it up as 5(3)=20(3)</p>

<p>Because the triangles are equilateral, you can break up the lenths of the bottom segment any way, multiply each respective side by three and add them together to find the answer.</p>

<p>For three… well it seems pretty obvious that is the number’s square root is the same as 40. So all you need to do is square 40 to find 1600.</p>

<p>Hope that helps</p>

4

<p>Hello again. Thanks A LOT for all the help. I just finished the next Math section, and I have questions about some problems:</p>

<p><a href=“http://imgur.com/BnR7s.png[/url]”>http://imgur.com/BnR7s.png&lt;/a&gt;&lt;/p&gt;

<p>The answer was E. I think I got this one wrong because I am always apprehensive about all of the above answers >_>.</p>

<p><a href=“http://imgur.com/Pzxuz.png[/url]”>http://imgur.com/Pzxuz.png&lt;/a&gt;&lt;/p&gt;

<p>The answer was B.</p>

<p><a href=“http://imgur.com/y62PI.png[/url]”>http://imgur.com/y62PI.png&lt;/a&gt;&lt;/p&gt;

<p>The answer was E.</p>

<p><a href=“http://imgur.com/MARlD.png[/url]”>http://imgur.com/MARlD.png&lt;/a&gt;&lt;/p&gt;

<p>The answer was C.</p>

<p>Thanks a lot!</p>

5

<p>For that last one, when you have multiple variables, I find it best to assign each one a numerical value. Let’s say x is .55 and y is 5.00, and that the call lasted two minutes. Plug in these values until you find the one that equals 2.
For choice C:
(5.55-X+Y)/Y
(5.55-0.55+5)/5
10 / 5 = 2.
:)</p>

6

<p>For the second one, start by drawing the line PT, with R in the middle and Q in the middle of PR.
PQ = QR
PQ + QR = PR = RT
QS = 10
PS = 19 = PQ + 10
PQ = 9, so QR also = 9.
this means that RS = 1 because 19 - 18 = 1.
Since PR = RT = 18, and RS is 1, RT - RS = ST,
or 18 - 1 = 17. Choice E</p>

7

<p>^I mean question #3 on that one…</p>

8

<p>For 2, assign a value for k and then solve for m.
Then divide the numbers that you used and you will get the ratio.
I used this…
K = 20
20% of 25 is 5
.75m = 5
m = 20/3</p>

<p>m/k = (20/3) / 20 = 1/3.
choice B.</p>

9

<p>Are you sure #1 is E? I don’t see how the midpoint can be outside of the circle if it’s between two points on a circle.</p>

10

<p>Yes. It is E, I have the official answer key. I think that they mean that if P is outside, it could be like this:</p>

<p><a href=“http://imgur.com/II5sB.png[/url]”>http://imgur.com/II5sB.png&lt;/a&gt;&lt;/p&gt;

<p>Not drawn to scale, obviously.</p>

<p>Anyways, thanks a lot. I shall post the last section later tonight. You guys seem to be having fun with this.</p>

11

<p>Oooooh! Haha. I read it incorrectly… Oh well, happy testing :)</p>

12

<p>Thanks again. I finally got the last section in:</p>

<p><a href=“http://imgur.com/CzBOU.png[/url]”>http://imgur.com/CzBOU.png&lt;/a&gt;
The answer for this was D.</p>

<p><a href=“http://imgur.com/Hi3g0.png[/url]”>http://imgur.com/Hi3g0.png&lt;/a&gt;
The answer for both was E.</p>

<p>For anyone interested, I got a 670 in the Math section in this practice SAT. That is an okay score for me :p</p>