Which  best  describes the relationship between the successive terms in the sequence shown? 9, –1, –11, –21, … the common difference is  –10.  the common difference is 10.  the common ratio is  –9. the common ratio is 9.

The common difference would be -10.

Step-by-step explanation: If it were +10 then it would be: 9, 19, 29, 39

If it had a common ratio of -9 then it would be: 9, -81, 729, -6561

It it had a common ratio of 9, then it would be: 9, 81, 729, 6561

the mistake in the pattern is that :

b. the decimal point was moved one too many place values each time

the correct pattern could be made by :

b. moving the decimal point to the right the same numbers of place values as the exponents