how to calculate velocity

Question

Two conveyor belts used to transport luggage at an airport runs parallel to each other but in opposite directions. Belt A has a velocity of 0.8m/s and belt B has a velocity of 0.4m/s. Calculate the velocity of belt A relative to the velocity of belt B. And calculate the velocity of belt B relative of belt A.

Answer 1

Velocity of belt A , v_A = 0.8 m/s

Velocity of belt B , v_B = - 0.4 m/s

Relative velocity of belt A to the velocity B, v_A/B = v_A  - v_B

                                                                     = 0.8 - (- 0.4)

                                                                      = 1.2 m/s

Relative velocity of belt B to the velocity A, v_B/A = v_B  - v_A

                                                                     =- 0.4 - (0.8)

                                                                     = - 1.2 m/s