Ijust need to know what problem chen is checking pls answer as quick as possible

What is the 9th term in the geometric sequence described by this explicit formula? an=-6. (2)(n-1) apex

The perimeter of △cde is 55 cm. a rhombus dmfn is inscribed in this triangle so that vertices m, f, and n lie on the sides cd , ce , and de respectively. find cd and de if cf=8 cm and ef=12 cm. the answer is not cd=20 and de=15. i have tried that one, it does not work.

Skie rented a boat for $16.50 per hour. her total rental fee was $49.50. for how many hours did skie rent the boat