Question 1035504
.
Find the sum
a + (a + 1) + (a + 2) + ... + (a + n - 1)
in terms of a and n.

Part (b): Find all pairs of positive integers (a,n) such that n>=2 and
a + (a + 1) + (a + 2) + ... + (a + n - 1) = 100.

note: >= means greater than or equal to.
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Learn about Arithmetic progressions and about the formula for the sum of arithmetic progression,
for example, from this lesson <A HREF=https://www.algebra.com/algebra/homework/Sequences-and-series/Arithmetic-progressions.lesson>Arithmetic progressions</A>.


Then apply it to your arithmetic progression.