Some Explanations Needed

Test Preparation SAT Preparation
1

<p>It would be great if someone could explain how to find/reasoning behind the answers to these questions. These questions are from Practice Test #5 in the 2nd edition of the BB. Answers to the questions are at the end.</p>

<p>Pg. 642- Section 2 (Math) #17:</p>

<p>In the xy-plane, like l passes through the origin and is perpendicular to the line 4x + y = k, where k is a constant. If the two lines intersect at point (t, t+1), what is the value of t?</p>

<p>A) -4/3
B) -5/4
C) 3/4
D) 5/4
E) 4/3</p>

<p>I didn't answer it because I couldn't figure out what to do.</p>

<p>Pg. 652- Section 4 (Math) #6</p>

<p>If m and k are positive and 10m^2k^-1 = 100m, what is m^-1 in terms of k?</p>

<p>A) k/10
B) k/90
C) sqrt(k)/10
D) 1/10k
E) 1/90k</p>

<p>I made a guess and got it right, but would like to know the correct way in solving questions like these.</p>

<p>Pg. 655- Section 4 (Math) #16</p>

<p>If a+2b is equal to 125 percent of 4b, what is the value of a/b?</p>

<p>These questions always seem to take so much longer to figure out, and really suck away time, so a quick way to solve these types of problems would be great.</p>

<p>Pg. 655- Section 4 (Math) # 18</p>

<p>In the xy-coordinate plane, the distance between point B (10,18) and point A (x, 3) is 17. What is one possible value of x? </p>

<p>This is just using the distance formula right? I think I just wrote down the formula wrong or something if that's true.</p>

<p>Pg. 657- Section 6 (Writing) # 7</p>

<p>The Poem's colorful images and its verbal wit give the reader pleasure</p>

<p>A) give the reader pleasure
B) please the one who is reading
C) gives pleasure to the one who reads it
D) give one pleasure in the reading of it
E) gives one pleasure in reading it</p>

<p>I put E because I saw wit was closer to give than images was.</p>

<p>Pg. 674- Section 9 (Critical Reading) #12</p>

<p>In line 42, "crush" most nearly means</p>

<p>A) Pressure
B) Crowd
C) Power
D) Infatuation
E) Critical Condition</p>

<p>I know this is from a passage, but hopefully someone else with the new BB could help me. I put A since none of the others even made sense, but I must have read that part of the passage incorrectly.</p>

<p>Pg. 677- Section 10 (Writing) # 11</p>

<p>Jesse passed the California bar examination last year, and he has been practicing law in California ever since.</p>

<p>A) and he has been practicing law in California ever since
B) since that time he has practiced law there
C) where ever since he practices law
D) he has been practicing law in California since then
E) and since then is practicing law there</p>

<p>I put E because I thought using California twice in the sentence is unnecessary. But I guess E is too ambiguous then without a specific location mentioned?</p>

<p>Answers (In order of appearance) :</p>

<ol>
<li>A</li>
<li>D</li>
<li>3</li>
<li>2, 18</li>
<li>A</li>
<li>B</li>
<li>A</li>
</ol>

<p>Any help is greatly appreciated.</p>

2

<p>17) </p>

<p>4x + y = k
y = -4x + k
line L is perpendicular to this, so its slope is the negative reciprocal of -4, which is 1/4
y = 0.25x + c, where c is another constant
since this line L passes through the origin, or the point (0,0), you know c is 0
y = 0.25x</p>

<p>(t, t+1)</p>

<p>substitute this into both equations
t+1 = (-4)(t) + k
t+1 = 0.25t
can’t solve the first one because it has two variables
t+1 = 0.25t
0.75t = -1
t = -1/0.75
t = -4/3</p>

<p>6) </p>

<p>10m^2k^-1 = 100m</p>

<p>what does this mean?</p>

<p>16)</p>

<p>a+2b = (1.25)(4b)
a+2b=5b
a=3b
a/b=3</p>

<p>18) distance formula</p>

<p>you know the Pythagorean theorem? a^2 + b^2 = c^2
that is how the distance formula works.
instead of memorizing it and eventually forgetting it, you should understand how it works</p>

<p>a is the length of a horizontal side, b is the length of a vertical side, and c is the length of the diagonal slant.</p>

<p>so x and y are a and b, and the distance is c.</p>

<p>to find x, you subtract the two x coordinates
to find y, you subtract the two y coordinates
the distance, which is given, is 17
(10,18) (x, 3)</p>

<p>10-x
18-3=15</p>

<p>so</p>

<p>(10-x)^2 + 15^2 = 17^2
(10-x)^2 + 225 = 289
(10-x)^2 = 64
10-x = 8 (took square root of both sides)
2 = x</p>

<p>7)</p>

<p>“images” and “wit” are both being described. it doesn’t matter which comes last</p>

<p>12) give us the sentence that the word is in</p>

<p>11) “California bar examination” is just a name. The second “California” is being used differently. Even if it wasn’t, it wouldn’t be incorrect. IT makes grammatical sense. and yes E would be amgiuous because a place wasn’t used in the same context as one that would allow a “there.”</p>

3

<p>6) 10(m^2)(k^-1)=100m</p>

<p>divide each side by 10m, you get</p>

<p>m(k^-1)=10</p>

<p>which translates to </p>

<p>m(1/k)=10</p>

<p>which then translates to </p>

<p>m=10k, so (1/m)=1/(10k)</p>

<p>please remember to put everything in parenthesis when needed; it helps you keep your work organized and helps others understand the problem.</p>

<p>If you want to avoid the convoluted algebra, you can substitute numbers for the variables. For example, say you set k=2, then:</p>

<p>10(m^2)(1/2)=100m</p>

<p>5(m^2)=100m</p>

<p>m^2=20m</p>

<p>divide each side by m, you get m=20. m^-1 is 1/20, so test the answer choices to see which one is true.</p>