Xpower6minus y6powerdivide xpower 3 minus y power 3

What is the nth term rule of the linear sequence below? 27 , 25 , 23 , 21 , 19 , . .

Ablock of wood is a cube whose side is x in. long. you cut off a 1-inch thick piece from the entire right side. then you cut off a 3-inch thick piece from the entire top of the remaining shape. the volume of the remaining block is 2,002 in3. what are the dimensions of the original block of wood?

Can any one me with the answers to these questions asap?