To find out how far Reagan biked in total on Thursday and Friday, you need to add the distances he biked on both days.
On Thursday, he biked 1.6 kilometers, and on Friday, he biked 7.1 kilometers.
So, you calculate:
\( 1.6 , \text{km} + 7.1 , \text{km} = 8.7 , \text{km} \)
Therefore, Reagan biked a total of 8.7 kilometers on Thursday and Friday.