Whats the answer to xy(xy^3)

He mass of a single atom of carbon can be found by dividing the atomic mass (12.01 g) by 6.022 x 10^23. which is the mass of a single carbon atom, correctly written in scientific notation with the correct number of significant figures?

If a seller prepaid the taxes of $4,400 and the closing is set for may 19, using the 12 month/30 day method what will the buyer owe the seller as prorated taxes?

Brad earns $12.75/hr and works 40 hours a week. what is his gross annual income?