Question

What is r the common ration in the geometic sequence 2, -14, 98, -687

Answer 1

r is -7

Explanation:

(I believe that you mistyped and meant that the fourth term in the sequence should be -686)

The easiest way to find the common ratio is to divide the numbers that are adjacent to each other

`(-14)/(2) =-7\\\\(98)/(-14) =-7\\\\(-686)/(98) =-7`

As you can see, when we divide a term by its previous term, we get -7 every time. This is our common ratio.