SOLUTION: 1 + 2 = 3 4 + 5 + 6 = 7 + 8 9 + 10 + 11 +12 = 13 + 14 +15 What would the last number of the 16th equation

Algebra ->  Sequences-and-series -> SOLUTION: 1 + 2 = 3 4 + 5 + 6 = 7 + 8 9 + 10 + 11 +12 = 13 + 14 +15 What would the last number of the 16th equation      Log On


   

Question 1106885: 1 + 2 = 3
4 + 5 + 6 = 7 + 8
9 + 10 + 11 +12 = 13 + 14 +15
What would the last number of the 16th equation
Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


1 + 2 = 3
4 + 5 + 6 = 7 + 8
9 + 10 + 11 +12 = 13 + 14 +15

Just to take the pattern one further:
16 + 17 + 18 + 19 + 20 = 21 + 22 + 23 + 24

The last numbers for the 1st, 2nd, 3rd, and 4th equations are 3, 8, 15, 24.

Any one of a number of methods can determine that these are the values of the polynomial f%28n%29+=+n%5E2%2Bn.

The last number in the 16th equation is then f%2816%29+=+16%5E2%2B16+=+256%2B16+=+272