Number 1 the squence the funtion model is geometric or the squence the funtion model is artgmetic number 2 the squence the funtion model is 2,-6,18,-54,162
the squence the funtion model is 2,-6,-18-,-54,-162
or is it the squence the funtion model is 2,-1,-4 ,-7,-10

numer 3 the common difference is 3
the common difference is -3
the common ratio is 3
or the common ration is -3