<p>there are actually 4 different slopes, a line with (2,5) and (4,-7), a line with (-2,5) and (4,-7), a line with (-2,5) and (-4,-7), and a line with (2,5) and (-4,-7), because solving for x each time gives you x=+-2 and x=+-4, but yeah the answer comes out right if you use 2 and 4, i would think collegeboard would use the points other than the obvious ( 2,5 & 4,-7) to get the answer, guess not</p>
<p>alright the answer is D ... -6</p>
<p>best way to do it...plug in -x^2 + 9 in graphing calculator (if you don't have one then it just takes longer)</p>
<p>go to table and see where the y value is 5 and -7 (since they give that to you)</p>
<p>now you know that (2,5) and (4, -7) are the points and (-2,5) and (-4,-7). Just picture the graph of the line going through both sets of points. The negative slope is obviously the smaller one and thus figrue out the slope (classic slope formula...or if you take like 5 min to create a simple slope program...your life just got 30 seconds easier and well you don't have to check as long as you plug in the points right)</p>
<p>any further questions ask away</p>
<p>time it should take you to do this problem...(40-50 sec) with method above...</p>
<p>time without method (2 - 3 min) without checking</p>
<p>nice. yeah thats exactly how I did it. just wanted to make sure I wasn't completely out of my mind or anything. Thanks to all who participated in what must have been a very brief, but stimulating math exercise! =P</p>
<p>lol alright I got a good one for you all to figure out. It was a number 20, many of you might have seen it but just for the hell of it let's see who can do it the fastest. </p>
<p>If xy = 7 and x-y = 5 then what does x2y - xy2 =</p>
<p>A. 2
B. 12
C. 24
D. 35
E. 70</p>
<ul>
<li>it's
x^2y - xy^2</li>
</ul>
<p>my bad</p>
<p>d ,</p>
<p>(x^2)y-x(y^2) = xy(x-y)</p>
<p>good job shash</p>
<p>yeah, D.</p>
<p>lame. i had to use my nifty TI89 to do it. i like your way better though Shash.</p>
<p>yeah in this case...the nifty ti-89 (which I love by the way) takes longer then just simple common sense....so rmbr USE THE CALC. WHEN NEEDED...and you'll be feeling good at the end of the test tmrw peace out</p>
<p>how would you do that on the ti-89??? i have one.. teach me this nifty stuff</p>
<p>Here's a good one...
How many orders pairs of integers (x,y) satisfy x^2 + y^2 < 9?
please reply FAST yay</p>
<p>this is what I counted (0,0) (0,1) (0,2) (1,0) (2,0) (1,1) (1,2) (2,1) (2,2) then you could also have the negative of each of those, so subtract the 0,0 and multiply by 2, then add in the 0,0. I think that'd be 17? sound right?</p>
<p>25 is that right?</p>
<p>21?</p>
<p>(0,0)
(1,0)
(-1,0)
(0,1)
(0,-1)
(2,0)
(-2,0)
(0,2)
(0,-2)
(1,2)
(-1,2)
(1,-2)
(-1,-2)
(2,1)
(-2,1)
(2,-1)
(-2,-1)
(1,1)
(-1,1)
(1,-1)
(-1,-1)</p>
<p>oops, i negated the zeros! lol</p>
<p>No definitely not right.
(0,0) (0,1) (0,2)
(1,0) (1,1) (1,2)
(2,0) (2,1) (2,2)
(0,-1) (0,-1)
(-1,0) (-1, 1) (1, -1) (-1, -1) (-1, 2) (1,-2) (-1,-2)
(-2,0) (-2, 1) (2,-1) (-2,-1) (-2, 2) (2,-2) (-2, -2)
===25..
answer is 25
i actually figured this question out just now</p>
<p>i initially put 21</p>
<p>AHH. i forgot the (2,2) combos!!!!!!! what a disgusting question.</p>
<p>hope these kinds of crazy questions wont be on the test tomorrow
They're not only hard, long, tedious and cannot be methodically done
but they also have many little tricks that you have to catch</p>
<p>yeah if anything i would like it to be 18 on the grid in section because then there'd be time to burn on something useless like this.</p>