PDF chapter test TRY NOW

Two APs have the same common difference. The first term of one AP is \(2\) and that of the other is \(7\). The difference between their \(10^{th}\) terms is the same as the difference between their \(21^{st}\) terms, which is the same as the difference between any two corresponding terms. Why?
 
Important!
This is a self-assessment task. Solve this question and assess the solution steps after completing the test on your own