What is [(x + 52.8) × 5-3.9343] / 0.5-10x?

What is [(x + 52.8) × 5-3.9343] / 0.5-10x?


[(x+52.8)×5-3.9343]÷0.5-10x
=[(x+52.8)×5-3.9343]×2-10x
=(x+52.8)×10-3.9343×2-10x
=10x+52.8×10-7.8686-10x
=528-7.8686
=520.1314



What does (520 + 1314) * 10 mean?