Question

Two arithmetic progressions have the same common difference. Their first terms are A and B respectively. The difference between their n^th terms is ______.

Answer 1

Two arithmetic progressions have the same common difference. Their first terms are A and B respectively. The difference between their n^th terms is А – В.

Explanation:

The n^th terms are A + (n – 1)d and B + (n – 1)d. 

Subtracting gives [A + (n – 1)d] – [B + (n – 1)d] = A − B, since the (n – 1)d terms cancel.