<p>this is from pt#5 sec 7 ? 18</p>
<p>if the sum of consecutive integers from -22 to x, inclusive, is 72, what is the value of x?
a. 23
b. 25
c. 50
d. 5
e. 94</p>
<p>the answer is b...which i'm not getting</p>
<p>what's the easiest way to solve this problem?</p>
<p>Well 72 is a positive number, so you know x has to be bigger than 22 because, if x=22, then the sum equals 0. So, it can't be d. It can't be a because the sum would be 23. 50 and 94 are obviously way too big. But if you try 25, you get 23+24+25 which is equal to 72. So, b is right.</p>
<p>Do you have a page number for this (so it can be added to the solutions</a> list)?</p>
<p>thanks!</p>
<p>its page 673</p>