Polar bears are listed as a threatened species. In 2005, there were about 25,000 polar bears in the world. If the number of polar bears declines by 1000 each year, in what year will polar bears become extinct? (2 points)
To find the year when polar bears will become extinct, we need to determine how many years it will take for the number of polar bears to reach zero.
Given that the number of polar bears declines by 1000 each year, we can set up an equation:
25,000 - 1000x = 0
To solve for x (the number of years it will take for polar bears to become extinct), we divide both sides of the equation by 1000:
25 - x = 0
On solving for x, we get x = 25.
Therefore, polar bears will become extinct in 25 years.
Hence, polar bears will become extinct in the year 2005 + 25 = 2030. Answer: \boxed{2030}.