December SAT Math Experimental

<p>Which one was the math experimental? Was it the one with the celcius question? That was a 16 question math section. Math was fairly easy so the curve should be harsh.</p>

<p>Was this the section that had the problem 9t^2-r^2=17? What is r+t?</p>

<p>For that question I just used guess and check and got t=3 and r=8:
9(3)^2 - (8)^2 = 17
9(9) - 64 = 17
81 - 64 = 17 → (17=17)
3+8=11</p>

<p>@kooshbag</p>

<p>Was this problem on the experimental section?</p>

<p>The above problem can be solved with a bit of algebra (assuming r,s are positive integers)</p>

<p>(3t-r)(3t+r) = 17</p>

<p>17 is prime, in which the only factors are (-1,-17) or (1,17). We discard the first solution (since 3t+r > 0) so we have</p>

<p>3t-r = 1
3t+r = 17</p>

<p>Solving gives (r,t) = (8,3), r+t = 11.</p>

<p>It might have been experimental because it appeared in one of the two math grid in sections and I think there’s only one that counts</p>

<p>And thanks for the explanation rspence (made a lot more sense than guessing and checking but ill take a speedy answer any way I get it lol)</p>

<p>9t^2-r^2=17</p>