Final answer:
The value of θ(u + v) is calculated by subtracting the angle of vector v from the angle of vector u, which is 120°.
Step-by-step explanation:
The value of θ(u + v) is the angle of the resultant vector when vector u and vector v are added. Given that the magnitude of vector θu is 130° and the magnitude of vector θv is 10°, their resultant is in a straight line since they are collinear but in opposite directions. The angle between u and v is 130° - 10° = 120°.