Question 55
Part a. The sum of the first eight terms of an arithmetic progression is $124$, and its first term is $5$. Find its first four terms.
Part b. The sum of the first seven terms of an arithmetic progression is $105$. The first, third, and seventh terms of this progression, in that order, are three consecutive terms of a geometric progression. Find the first four terms of the arithmetic progression.
Part b. The sum of the first seven terms of an arithmetic progression is $105$. The first, third, and seventh terms of this progression, in that order, are three consecutive terms of a geometric progression. Find the first four terms of the arithmetic progression.