How do you do these problems!!! Please help!!!!!!

Test Preparation
1

<p>If A is the sum of the integers from 1 to 50 and B is the sum of the integers of 51 to 100 what is the value of B - A? I do not know how to do these at all. It says the answer is 2500</p>

2

<p>to find the sum of any series of numbers, you first add the first and last numbers of the series together, then multiply that sum by the number of values included in the series, then divide that by two. so in the case of 1-50, you would do</p>

<p>1+50 = 51</p>

<p>51 X 50 = 2550</p>

<p>2550/2 = 1275</p>

<p>so the sum is 1275, you then do the same thing for 51-100, which is 3775, and you subtract the first sum from that, and you do get 2500.</p>

3

<p>or you can do sth like this. you see that, B-A means (51-1) + (52-2)+ ... (100-50)= 50 * 50=2500
much easier way.</p>