I need help can someoe explain how to do this?

The size of a certain cell is 2.5*10^-9m. another cell is 1.5*10^3 times larger. how large is the larger cell in scientific notation?

The first floor of marcus’ house is 1,440 square feet. he will cover 1,033 square feet with wood and the rest with tile. a box of tiles will cover 11 square feet. how many boxes of tile does marcus need to buy to cover the floor?

For g(x) = 5x - 3 and h(x) = [tex]\sqrt{x}[/tex], find (g · h)(4)