Draw 2 triangles from the vectors
vector a is 12m @ 40 degrees
vector b is 9m @ 20 degrees
Any line that's not straight can be a hypotnuse.
Based on the graph, you need cosine to find x since cos=hyp/adj and adj is moving in the x axis.
a goes in the positive direction and b goes in the negative direction, so
As given in the question
So the component of