ACT math question

Test Preparation
1

<p>on the math do you guys/girls remember number 55. it went like </p>

<p>x^2 -x = something</p>

<p>a.) -20
b.) -1
c.) 0
d.) 12
e.) 16</p>

<p>i dont really remember how the question was asked but i am positive the answers were c d and e. can anyone help me clear up this question</p>

2

<p>i think i got 12.</p>

<p>(-3)^2 - (-3) = 9 + 3 = 12
4^2 - 4 = 16 - 4 = 12</p>

3

<p>What did it equal though, rather what was the "something." I remember graphing it, and using the intersection method.</p>

4

<p>It said one of the numbers had to be negative, and one positive. Therefore, that rules out 0.</p>

<p>Oh, and the equation was: x^2-x=b.</p>

5

<p>it was 12, and that was the fifth choice.</p>

<p>I remember I tested on my 89 and only 9 and 12 gave one positive and one negative result. the results when i plugged in 12 were integers</p>

6

<p>whoa vagrant star how did u use a TI-89, those are illegal on this test.
does anyone know exactly how the question went?</p>

<p>i ended up putting 12 :) as my answer</p>

7

<p>I'll paraphrase it, not verbatim of course.</p>

<p>Given two integers, one positive and one negative, in the equation x^2-x=b, what is a possible value for b?</p>

8

<p>thank you hypernovae</p>

9

<p>(3)^2 - (-3) = 12
(-1)^2 -(1) = 0
(4)^2 - (-4) = 20</p>

<p>look three answers...am i doing something wrong or am i reading the question wrong.</p>

10

<p>It was still in my calculator.</p>

<p>The question had something to do with some power 5,677 trillion (5.677 x 10^15) minus another source of power 2,884 trillion (2.884 x 10^15).</p>

<p>Subtracting gets an answer of 2.793 x 10^15.</p>

11

<p>thanks hypernovae for that answer...got it right</p>

<p>i just edited post#9 and i still dont get that question #55</p>

12

<p>sorry messed up again... there should not be a third equation cuz the answer choice is neg and not pos. so i cant see how plugging in -1 does not make the result 0</p>

13

<p>the question was:</p>

<p>Xsquared - X = b</p>

<p>One value of x had to be negative and one had to be postive; both X values also had to lead to the same end result, or B.</p>

<p>If the positive one was 2, then 4-2 = 2, so B = 2</p>

<p>If the negative one was -1, then 1- (-1) = 2</p>

<p>That's why I put -1.....is that right?</p>

<p>OOOO...I didn't read the question properly...</p>