Whats the answer and how so i solve for it?

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?

Which statement about the relative areas of δabc and δxyz is true? the area of δabc > the area of δxyz the area of δabc < the area of δxyz the area of δabc = the area of δxyz more information is needed to compare.

Suppose y varies directly with x. write a direct variation equation that relates x and y. then find the value of y when x=12 y=7 when x=3