I need help with this. Can you please show all work.

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?

Use sigma notation to represent the following series for 9 terms.

Can you make 1000, using only eight 8’s? if you had your choice, would you rather have 5 million dollars, or 1 penny, doubled every day for a month?