<p>for this question: g(x) = x(x-1), g(m+2) = 12, solve for m</p>
<p>x(x-1) = 12 and solve for x… i got 4 or -3???..</p>
<p>How does the obtuse triangle one have answers between 10 and 14???
Where did you get 10 from? And why can’t it be 10?
All we had to know was the triangle inequality theorem. Since the sides were 6 and 8, the third obviously could not be more than 14. Also, since the side of corresponding obtuse angle was the longest, the answer had to be greater than 8. I picked 10.</p>
<p>if you foil it out you get x^2 + y^2 + 2xy </p>
<p>you know all the parts. just plug in.</p>
<p>2xy = 2(a - 10)
x^2 + y^2 = a
a+2(a - 10)=3a - 20</p>
<p>^yes i think it was</p>
<p>@Molly: Yeah, it was 3a-20.
If x^2 + y^2 = a,
and (x+y)^2 = x^2 + 2xy + y^2,
and xy = a - 10,
then 2xy = 2a -20,
so then you add 2xy to the left side, and 2a - 20 to the right (so it’s still a balanced equation).
So you get x^2 + 2xy + y^2 = a + (2a-20)
So (x+y)^2 = 3a-20</p>
<p>Yes it was. That’s what I put and that’s why I’m so damn angry right now.</p>
<p>was 3a-20, answer choice D?</p>
<p>the triangle one was 15.</p>
<p>@Pap: It can’t be 10 because 6-8-10 is a right triangle. It specifically says the angle is greater than 90, so therefore it has to be greater than 10, but because of triangle inequality, 6+8 has to be greater than the third side so your answer must be BETWEEN 10 and 14.</p>
<p>^^I don’t think 15 was a choice. I think I got 16. Maybe I’m just having a memory fail though…</p>
<p>If the answer to the hall B was 290, then freshman couldn’t have been 45 as that isn’t 20% of 290. The problem stated that 20% was allotted to the freshman.</p>
<p>For…x^2 + y^2 = a and xy = a - 10…
(x+y)^2 = x^2 + 2xy + y^2.
We know that x^2 + y^2 = a
and since xy = a - 10, 2xy = 2a - 20.</p>
<p>So, a + 2a - 20 = 3a - 20.</p>
<p>jolly- the answer was 2.</p>
<p>because it’s (m+2)(m+2-1)=12
m^2+3m+2=12
m^2+3m-10=0
(m+5)(m-2)=0</p>
<p>m is -5 or 2. Answer is 2 since its positive.</p>
<p>was 3a-20, answer choice D? anyone know?</p>
<p>wasnt xy=-10
?</p>
<p>Was 6 an incorrect answer choice for the 5 5 6 triangle</p>
<p>@Web: xy couldn’t have equaled a negative number because it was abs(xy).</p>
<p>@Linger: I think so? Either D or E, I can’t remember now.</p>
<p>was “11-3x-y” answer choice B?</p>
<p>for the one where m was 2, was that one a multipple choice or grid in and was 12 also a choice?</p>
<p>“How does the obtuse triangle one have answers between 10 and 14???
Where did you get 10 from? And why can’t it be 10?
All we had to know was the triangle inequality theorem. Since the sides were 6 and 8, the third obviously could not be more than 14. Also, since the side of corresponding obtuse angle was the longest, the answer had to be greater than 8. I picked 10.”</p>
<p>@papapia. it can’t be 10 because then the triangle becomes a 6-8-10, right angle triangle. The angle had to be obtuse…</p>
<p>@Linger: m=2 was a grid-in, I think. And now that I think about it, I’m pretty sure 3a-20 was D.</p>