Since the musician earns 0.09foreachdownload,themusicianearns0.09d$ dollars when the song is downloaded dtimes.
0.09d+0.002s
Similarly, since the musician earns 0.002eachtimethesongisstreamed,themusicianearns0.002s$ dollars when the song is streamed stimes.
Therefore, the musician earns a total of0.09d+0.002s dollars when the song is downloaded dtimes and streamedstimes.