Answer:
Note that [tex]PQ + QR = PR[/tex]:
Once:
[tex]PR = 15x-11\\PQ=3x+6[/tex]
[tex]PQ + QR = PR\\\\(3x+6)+QR=(15x-11)\\\\QR=(15x-11)-(3x+6)\\\\QR=15x-11-3x-6\\\\QR=12x-17\\[/tex]
Therefore, the answer is letter B
