help on math question??

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1

<p>If the sum of the consecutive integers from -22 to x, inclusive is 72, what is the valueof x?</p>

<p>Apparently the answer is 25. However, that doesn't make any sense to me. IF xis 25, then wouldn't the sum be 3?</p>

2

<p>No. -22+(-21)+(-20)+...+20+21+22 = 0, right? So by the time you've gotten to 22, you're at 0. Now, 23+24+25=72.</p>

3

<p>-22 + 25 = 3
-21 + 24 = 3
and so on.
There are 48 integers between -22 and 25 (including -22 and 25), which means there are 24 pairs that add up to 3
24 X 3 = 72</p>

4

<p><a href="http://talk.collegeconfidential.com/sat-preparation/550344-sat-math-question-algebra.html?highlight=integers+from+to+x%2C+inclusive+is+72%5B/url%5D"&gt;http://talk.collegeconfidential.com/sat-preparation/550344-sat-math-question-algebra.html?highlight=integers+from+to+x%2C+inclusive+is+72&lt;/a&gt;&lt;/p>

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