Respuesta :

Answer:

y = 7

QR = 21

Step-by-step explanation:

"bisects" means cuts in half, or that Q is exactly in the middle of PR.

PQ + QR = PR

Well, if PR is 42, then QR is 21 (that's half)

PQ = QR because the two halves are the same.

3y = 21

y = 7