Is the relation a function? explain

What is the simplified form of (3.25x10^3)(7.8x10^6) written in scientific notation?

The height of a birch tree, f(x), in inches, after x months is shown in the graph below. how much does the birch tree grow per month, and what will be the height of the birch tree after 10 months? a. the birch tree grows 1 inch per month. the height of the birch tree will be 16 inches after 10 months. b. the birch tree grows 2 inches per month. the height of the birch tree will be 26 inches after 10 months. c. the birch tree grows 3 inches per month. the height of the birch tree will be 36 inches after 10 months. d. the birch tree grows 2 inches per month. the height of the birch tree will be 24 inches after 10 months.

Evan walked 5/8 mile to his friends house.then together they walked 7/12 mile to the movie theatre.which pair of fraction can evan use to find how far he walked in all?