Please help will give BRAINLIEST

If i think about this question right i think its (3x+15)
Step-by-step explanation:
Answer:
(3x + 5) + (x +3) = 180 sum of angles on a
straight line
3x + 5 + x + 3 = 180
3x + x + 5 + 3 = 180
4x + 8 = 180
4x = 180 - 8
x = 172/4
x = 43
PQR = 3x + 5 = 3(43) + 5 = 129 + 5 = 134