Need help with 2 maths and 1 writing question (Pictures included!)

Test Preparation SAT Preparation
1

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<a href="http://img267.imageshack.us/img267/4955/08102009336.jpg%5B/IMG%5D"&gt;http://img267.imageshack.us/img267/4955/08102009336.jpg

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<p>(Correct answer = E)</p>

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<a href="http://img230.imageshack.us/img230/2379/08102009337.jpg%5B/IMG%5D"&gt;http://img230.imageshack.us/img230/2379/08102009337.jpg

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<p>(Correct answer = B)</p>

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<a href="http://img33.imageshack.us/img33/8771/08102009338.jpg%5B/IMG%5D"&gt;http://img33.imageshack.us/img33/8771/08102009338.jpg

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<p>(Correction ans = B)</p>

2

<p>First one: Just take the reciprocal and substitute y for x.</p>

3

<p>Third one: (B) is the only parallel answer.</p>

4

<p>Could you explain your steps/answer in more detail please? I’m quite a noob at times :stuck_out_tongue: Thanks in advanced!</p>

5

<p>Second one: multiplied out left side: x2 + 8k - 8x - kx = x2 - 5kx + m
subtract x2 from both and simplify: 8k - 8x = -4kx + m
equation true for all values of x, so i put in x=0: 8k = m
then i went back to second step and put in x=1: 12k = m + 8
substituted 8k = m into 12k = m + 8: 12k = 8k + 8
simplify and solve for k: 4k = 8, k=2
substitute 2 into 8k = m: m = 16</p>

6

<p>^Oh my, thank you so much!!! Clear explanation too :D</p>

7

<p>Here’s a good explanation for the first one: if x is inversely proportional to y, then x=k/y</p>

<p>Square both sides because you want your equation to be 1/x^2. So it would be x^2= k^2/y^2. Then flip x^2 so you get 1/x^2 and do the same on the right so you get y^2/k^2. This latter side of the equation is directly proportional to 1/x^2. Since k is a constant, 1/k^2 would be the whole constant in the equation. You’re left with y^2 (E)</p>

8

<p>^ Genius :D</p>

<p>Thank you!</p>