Hello These Are Biology Questions For My Ecology Class That I Have Do Not Know H

Hello these are biology questions for my ecology class that I have do not know how to start with. Can work be shown so I can figure out how to do them.Thank you!

a)The population growth rate due to the difference in births and deaths in the U.S. is estimated to be 0.6% per year (r =0.006). Given a 2001 population size of about 285 million, calculate the projected population size in 2025 and 2050.

b) Immigration from legal sources (660,000 in 1998) and illegal sources (estimated to be about equal to legal immigration) minus emigration (usually less than 200,000 per year) adds about 1 million people per year to the U.S. population. The total population growth rate from all sources in thus about 0.9% per year (and immigration is thus responsible for about 1/3 of this growth). Given this rate, calculate the projected U.S. population size in 2025 and 2050.