SOLUTION: The sum of the first to our members is 1+3=4. Some of the first three numbers is 1+3+5=9. What is the sum of the first eight odd numbers? How does a sum of the first eight even nu

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: The sum of the first to our members is 1+3=4. Some of the first three numbers is 1+3+5=9. What is the sum of the first eight odd numbers? How does a sum of the first eight even nu      Log On


   

Question 1025208: The sum of the first to our members is 1+3=4. Some of the first three numbers is 1+3+5=9. What is the sum of the first eight odd numbers? How does a sum of the first eight even numbers compared to the sum of the first eight odd numbers? Explain why this is so?
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
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The sum of the first two odd numbers is 1+3=4. The sum of the first three odd numbers is 1+3+5=9. What is the sum of the first eight odd numbers?
How does a sum of the first eight even numbers compared to the sum of the first eight odd numbers? Explain why this is so?
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1.  I edited your post.


2.  The sum of the first n odd integer (positive) numbers is 
    1 + 3 + 5 + . . . + (2n-1) = n%5E2.   
    So, the sum of the first 8 odd integer (positive) numbers is 8%5E2 = 64.


3.  The sum of the first n even integer (positive) numbers is 
    2 + 4 + 6 + . . . + (2n) = n*(n+1).

    So, the sum of the first 8 even integer (positive) numbers is 8*9 = 72.


See the lesson Problems on arithmetic progressions (Problems 2 and 3) in this site.