Final answer:
The mathematical operation in the question involves multiplying 5 by 4, which equals 20. The rest of the question refers to an experience in the video game Halo Reach, which is not related to Mathematics.
Step-by-step explanation:
The question '5x4 any of the boy remember the feeling of playing the last mission in halo reach what was it you vs 50 covented?' appears to be partially about Mathematics, specifically an arithmetic operation. The '5x4' in the question refers to the multiplication of the numbers 5 and 4.
To solve 5x4, you multiply 5 by 4, which equals 20. The rest of the question seems to be unrelated to the mathematical computation and may refer to a personal experience in the video game Halo Reach, which is not within the Mathematics context.