How does ray ab and ac form both a line and angle

Rays AB and AC both have a point in common. That is the A point or normally called the vertex. From the point both go in different directions making a distance between both. This distance has a degree in which it separated that forms the angle. This also forms a line because both rays, in theory, are lines. They just tend to continue to infinity in just one direction.

3x+9+4x+x=8x+9that's the answer for your question.