Who Is The Observer?

Classical Mechanics Level 2

Two space shuttles are in co-linear movement, and they will collide one against the other.

If the space shuttle A is traveling with a velocity of $0.7c$ and the space shuttle B is traveling with a velocity of $0.8c$ . If you are in Shuttle A, what is the velocity of B relative to you?

Definition: $c$ is the speed of light.