Need help with this reverse 45-45-90

Bradley hikes 12 miles in 3 hours. in relation to bradley’s hike, which statement describes the expression

Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.

Which of these sequences is a geometric sequence a 1,2,4, 7, 11, 16, 22. b. 2.4.8.14.22.38 c.3.6.9. 15.18,21 d. 3,9,27,81,243,729,