Hi Rita,

Let me try a different example

3ⁿ/5ⁿ⁺¹

The letter n tells you the term number so n = 1 gives the first term, n = 2 gives the second term, n = 3 gives the third term and so on. thus

first term: 3¹/5¹⁺¹ = 3/5²
second term: 3²/5²⁺¹ = 3²/5³
third term: 3³/5³⁺¹ = 3³/5⁴
fourth term: 3⁴/5⁴⁺¹ = 3⁴/5⁵

Thus the first 4 terms are 3/5², 3²/5³, 3³/5⁴ and 3⁴/5⁵

You might expand the terms and write them 3/25, 9/125/, 27/625 and 81/3125 but I find the first form more useful. In particular when I look at 3/5², 3²/5³, 3³/5⁴ and 3⁴/5⁵ I see that each term is 3/5 times the previious term and hence the common ratio is 3/5.

I hope this helps,
Penny