Math for Educators
posted by Carol .
The first difference of a sequence is 8, 12, 16, 20,... The sum of the first two terms of the original sequence is 14. Find the first three terms of the original sequence.
The first term of the original sequence is? 4
What is the second term of the original sequence? 8
What is the third term of the orignal sequence? ???

the first sum is 14...
differences are always multiple of 4, or
2,3,4,5... so going backwards, 3,2,1 times 4..
first term has to be 4, the second 8 more
4,8, the third term is 12 more
4,8,20 and so on.