Need help on 2 sat math problems!

Test Preparation SAT Preparation
1

<p>First one:

<a href="http://184.72.239.143/mu/617bd1d4-56fd-0fe2.jpg%5B/IMG%5D"&gt;http://184.72.239.143/mu/617bd1d4-56fd-0fe2.jpg

</a><br>
Second one:

<a href="http://184.72.239.143/mu/617bd1d4-573d-3a82.jpg%5B/IMG%5D"&gt;http://184.72.239.143/mu/617bd1d4-573d-3a82.jpg

</a></p>

<p>Thanks!</p>

2

<p>I couldn’t see number one but number two would be B.</p>

3

<p>The answer is E, </p>

<p>(a+b)^1/2 = (a-b)^-1/2</p>

<p>Square both sides</p>

<p>a+b = (a-b)^-1</p>

<p>a+b = 1/(a-b)</p>

<p>Multiply both sides by (a-b)</p>

<p>(a+b)(a-b) = (a-b)/(a-b) = 1</p>

<p>(a+b)(a-b) = 1</p>

<p>Multiply it out</p>

<p>a^2 + ab - ab - b^2 = 1</p>

<p>The middle ab’s cancel out. You’re left with…</p>

<p>a^2 - b^2 = 1</p>

4

<p>as for number 2, you simply have to plug in numbers :smiley:
i chose -1 for y and -2 for x because those are easy</p>

5

<p>Oh okay I understand now, thank you!</p>

6

<p>12-B, isn’t it?</p>