who wants to help me with some ACT math?

<p>Hey all! I want my ACT score to be 32+, (shooting for a 34, but will be pleased with a 32) and since math is my lowest score, I figured I'd start there. I can score high 30s for the other areas, but math is one that I am kind of struggling with.
I took the math test found here: <a href="http://www.act.org/aap/pdf/Preparing-for-the-ACT.pdf"&gt;http://www.act.org/aap/pdf/Preparing-for-the-ACT.pdf&lt;/a&gt;&lt;/p>

<p>And I missed questions: </p>

<h1>2 (silly mistake with a negative, don't need to go over this one, lol)</h1>

<h1>20</h1>

<h1>30</h1>

<h1>33</h1>

<h1>34</h1>

<h1>37</h1>

<h1>38</h1>

<h1>42</h1>

<h1>44</h1>

<h1>47</h1>

<h1>51</h1>

<h1>52</h1>

<h1>55</h1>

<h1>60</h1>

<p>A majority of these are Plane Geometry/Trig, and the Intermediate Algebra/Coordinate Geometry questions, with a few Pre-Algebra thrown in. The reason my geometry skills are bad is because I had a horrible geometry class this year and the teacher did not want to teach. Plus I only had it for half a semester, and I doubled up on math so I took Geometry and Algebra 2. Now I will be in Pre-Calculus this year and I still feel a little behind due to my bad geometry experience. </p>

<p>So, if anyone would care to go over these problems with me and tell me how to do them, that would be fantastic! I know CC is an amazing resource for people who need help with all things college related, so I had no idea where else to go. (Considering its summer break, and I have no math teachers available to me) </p>

<p>My email is: <a href="mailto:academicgeneral@gmail.com">academicgeneral@gmail.com</a>, in case anyone wanted to reach me via email. Lol.</p>

<p>@tremndose I haven’t worked through this test yet, but their is a second online ACT exam that provides explanations. Have you taken that one?</p>

<p><a href=“The ACT Test for Students | ACT”>The ACT Test for Students | ACT;

<p>@banjoand Unfortunately, I have already taken that. That was the first set of questions I found, which lead me on a quest to find as many ACT resources as possible. </p>

<p>Thanks for the help, though!</p>

<p>Ok, lets take a stab at #20. Tell me if this is helpful and I can keep going.</p>

<p>==================================================================
Imagine a small rectangle. Its width is 3, its length is 2. Its area is 6.</p>

<p>OOO
OOO</p>

<p>The large rectangle has the same width, but is 3 times longer. It would look like this:</p>

<p>OOO
OOO
OOO
OOO
OOO
OOO</p>

<h1>If you count the area of the large rectangle, you find that it is 18, three times larger than the small rectangle. So k equals three.</h1>

<p>I used three strategies to solve this problem. </p>

<ol>
<li>I read the instructions carefully and understood the setup.</li>
<li>I drew some example rectangles based on the problem setup. In a real exam I would just imagine them, but for practice its often good to actually draw them. This lets you make sure your imagination is not running wild.</li>
<li>They didn’t tell me the length and the width of the small rectangle so I just made them up. This isn’t necessary, but it is often easier to work with concrete numbers than vague abstractions. Certainly better for posting here!</li>
</ol>

<p>I just took a practice ACT today and it was this exact one. I know I got the majority of the math questions right, so I can help you with them :)</p>

<p>@banjoandstuff Yeah! That’s super helpful. I think I understood the question, but I got my small and large rectangles mixed up. I put G, which is 1/3. I also plugged in numbers because I figured it would help, but alas, I just got my shapes mixed up. That’s an awesome tip, though! I never though about drawing it out like that.</p>

<p>@hopefulrm Please do! Just help with whatever you feel like helping with. I am currently going back over and I am seeing many, many dumb mistakes (a majority involving me not keeping up with negatives. :/)</p>

<h1>20 - J - Explained well above.</h1>

<h1>30 - K - Each side of this square is 3cm long. If one vertex is at (2,0), another vertex must be at either (5,0), 3cm to the right, or (-1, 0), 3cm to the left.</h1>

<h1>33 - D - If you isolate y to get an easier form of this equation, you’ll get y = 2x - 4. You can then graph that and see that it goes through quadrants I, III, and IV.</h1>

<h1>34 - F - You can graph this and use the table of coordinate points to see where the equation goes through (1, x). If you look at the table, you can see that it goes through (1, 4). So, x must be 2.</h1>

<h1>37 - B - The question is asking for the perimeter of the outside of the figure. You know that one side of the square is 8cm long. Two sides of the square are included in the outside of the figure, so it must be 16 + something. So you’re choosing between B and C. I’m not sure if there is a technical way to choose between these. I chose B because it seems like 8 is around the diameter of the circle. So, 4 would be approximately the radius, and the circumference (perimeter of the circle) would be about 8pi.</h1>

<h1>38 - G - If you divide EGFH into triangles like the rest of the figure, you can see the ratio. EGFH has 2 triangles, and the shaded region has 6. The ratio of that would be 2:6, and reduced, 1:3.</h1>

<h1>42 - F - You can see this through right triangle trig, aka SOH-CAH-TOA.Tan = opposite/adjacent. You are looking for the side from the boat to the dock. You’re not looking for the hypotenuse, which SOH and CAH both include, so you would use tangent. Using the 52º angle, you go opposite that to the side you’re looking for and then adjacent to the 30 mile length side. (Sorry if that doesn’t make much sense)</h1>

<h1>44 - H - If you can reflect a line to another line and find it unchanged, it’s a line of symmetry. The lines of symmetry in that figure is basically all sides of both squares. So 8.</h1>

<h1>47 - C - I’m not 100% sure on this one. A bisector cuts an angle into to equal parts, as AE does to <BAC. I just figured <AEC would be a right angle.</h1>

<h1>51 - C - So, for every hour that Marcia spends making frames, she gives $3. Above in the little passage, it says it takes her 2 hours to make 1 small frame and 3 hours to make 1 large frame. In this week of December, she’s made 4 large frames and 2 small frames. So she has spent 12 hours on the large frames and 4 hours on the small frames for a total of 16 hours. Since she spent 16 hours making her frames, she will donate $48. Also in the passage part above, we’re given an equation for her profit, p = 30s + 70l, s for the small frames and l for the large frames. We know those values, so we can set up the equation</h1>

<p>p = 30(2) + 70(4) and get a profit of $340. The question is asking what percent of that week’s profit did Marcia donate. 14% of 340 is 47.6, which is the closest value to the $48 she actually donates. </p>

<h1>52 - I’m not sure about this one. I think you have to figure out what the graph is telling you and use those values in the profit equation, but it was confusing to me.</h1>

<h1>55 - C - You can pick values for x and y and test these. For example, if x is 2 and y is -5: (A) 2/-5 is not greater than 1. (B) |2|^2 = 4 is not greater than |-5|. © (2/3) - 5 is greater than (-5/3) - 5, so that works.</h1>

<h1>60 - F - If a number is 5 units from -3, then the difference between the number and -3 is 5. If the number is to the right of -3, x-(-3) = 5 and if the number is to the left of -3, then -3 - x = 5 or x-(-3) = -5. In either case the absolute value of x-(-3) is 5 so the solution set is |x-(-3)| = 5, or choice F.</h1>

<p>Here’s a visual to explain #30. Does it make sense?</p>

<p><a href=“https://dl.dropboxusercontent.com/u/1131693/bloodrop/Screenshot%202014-07-29%2013.58.31.png”>https://dl.dropboxusercontent.com/u/1131693/bloodrop/Screenshot%202014-07-29%2013.58.31.png&lt;/a&gt;&lt;/p&gt;

<p>I can keep going, but if you have already discovered some mistakes on your own, would you list the ones you are still having problems with so I don’t do unnecessary work?</p>

<p>Looks like @hopefulrm did a great job explaining the others. If there are any that still don’t make sense ping me and I’ll try to offer a second explanation.</p>

<p>@hopefulrm I should mention I did #33 correctly, but I forgot to put my negative and divided by +2 instead of -2. Sigh… on #34, I now see I could have just plugged 1 in for x and and 2a in for y and did it that way, but I wasn’t thinking about it. UGH. I also guessed on several and got them right, but it doesn’t do me any good if I don’t know how to do them for later. Do you know how to do questions: #48, #56, #57, #58, #59? These are all near the back and the harder questions, lol. </p>

<p>Thanks for your input! It was incredibly helpful.</p>

<p>@banjoandstuff Thanks for your help!! I feel pretty good about the ones that I missed now that I have a different viewpoint and can use a different strategy to tackle the questions. </p>

<p>Awesome, good luck with your studies!</p>

<h1>48 - H - I’m not sure of a technical way to do this. To find an arc length, you can do the circumference of the circle * the angle in the arc section / 360. But you aren’t given a radius or diameter or anything to help with the circumference. I sort of just visualized it. You can see that QPT and RPS are congruent, and in QPR and TPS, it seems like you can fit two of the sections of QPT/RPS in both QPR and TPS. So, that’s 6 angles that are around the same measure, and 360/6 is 60. There’s probably something with the 30º you can use, but I’m not sure.</h1>

<h1>56 - J - I’m not really sure about this one. Since both triangles have two of the same sides, I figured that their areas would be around the same, so I chose J. Maybe someone else can be more helpful with this one.</h1>

<h1>57 - E - You’re looking for BC. Since you only know one angle measure and two sides, you have to use the law of cosines to figure it out. You know two sides, so you’ll be solving for the third side, or side c. As it says there, the law of cosines says that c^2 = a^2 + b^2 - 2ab * cos<C. So, you can just fill in the values and get c^2 = 12^2 + 18^2 - 2(12)(18) * cos<40º. To solve, you take the square root of the whole right side of the equation and get answer choice E.</h1>

<h1>58 - G - An arithmetic sequence involves adding or subtracting the same value from each previous value to get the next value. An example is 2, 4, 6, 8, where you are adding 2 to get each next term, so the common difference is 2. In this question, we are given that the 6th term is 8 and the 10th term is 13. So, you have to find the common difference that is being added between each term. If you do (13-18)/4 (because 4 is the difference between 6 and 10), you get 1.25, which is the difference. You can check this by adding from 8 and see if you get 13 four terms later (and you do). To solve the question, just move backwards and subtract 1.25: the 6th term is 8, the 5th term is 6.75, the 4th term is 5.5, the third term is 4.25, the second term is 4.25, and the first term is 1.75. It asks for the sum of the first four terms, so you add them up and get 14.5.</h1>

<h1>59 - You can test these by plugging in x. You are told that m and n are both integers, x is -3, and the equation given is x^2 + mx + n = 0. If you plug in x, you get 9 + 3m + n = 0. You can go through the answers and plug in values for m, and then see if you are left with an integer for n.</h1>

<p>@hopefulrm You are incredibly awesome! Thank you so much for helping me with this! I am so mad at myself. I could do 57 if I had just taken the time to plug in things instead of freaking out. Also on number 58 UGH. I knew how to do it but I just completely forgot how. I got to 9+3m+n=0, but I totally didn’t plug in the numbers listed with variable m. Gah. I so could have done half of these if I would have just thought the question through. </p>

<p>Thanks for your help, again!</p>