Answer:
Sydney has -50 dollars in her account.
Explanation:
If Sydney had $150 in her bank account. Then, she bought a bike for $200. To know her current bank account balance, than we must subtract $200 from $150.
150 - 200 = -50 dollars
This question doesn't really make sense though, since you can't buy something that you don't have enough money to buy.
Either way, I hope this helps! :D