In the figure, the magnitude of vector A⃗ is 18.0 units, and the magnitude of vector B⃗ is 12.0 units. What vector C⃗ must be added to the vectors A⃗ and B⃗ so that the resultant of these three vectors points in the − x-direction and has a magnitude of 7.50 units? a) Use vector components to find your answer, and express vector C⃗ by giving its magnitude.
Enter your answer numerically.