For some reason, brainly deleted my answer even though I provided an explanation AND used detail. The reason this is the answer is because you take away all the zeros, resulting in 2871 * 10^6. Then, you take away 3 more places to make it 2.871 * 10^6 * 10^3. That simplifies to 2.871 * 10^9. Scientific notation is like a simplified form, but using exponents that have a base of 10.
add a decimal point at the end of the number ( 2,871,000,000.) then count how many places it takes to move the decimal point between the first and second number (2.8) then write the rest of the numbers higher than "0" after, giving you the 2.871
to show that the number written is in scientific notation you add 10 to the power of the amount of times you moved the decimal place. In this case, because the decimal point was moved a total of 9 times, it would be 10 to the 9th power (10^9).
