Question

How do you write a rule for the nth term given 28, 128, 228, 328, ...?

Answer 1

`n^(th)` term of the series is `100n-72`

Explanation:

The series `28, 128, 228, 328, ...` is arithmetic series whose first term `a` is `28` and difference between a term and its preceding term `d` is `100`.

`n^(th)` term of an arithmetic series whose first term is `a` and common difference is `d` is `a+(n-1)d`.

Hence for above series it is `28+(n-1)100=28+100n-100=100n-72`