The video shows a man standing in front of a blackboard with mathematical equations written on it. He is wearing glasses and a camouflage shirt. The man is speaking to the camera, and his expressions and gestures suggest that he is explaining the equations on the board. The blackboard has several mathematical equations written in white chalk, including one that reads "R(x) = A(x) + B(x)". The man appears to be a teacher or professor, and the setting suggests that he is giving a lecture or tutorial on the subject matter.