What is the value for y √2y+3=11

Explain how you can show five less than a number using an algebraic expression

Me because i don't understand how to do it.: )

Abank manager wants to encourage new customers to open accounts with principals of at least $2 comma 500. he decides to make a poster advertising a simple interest rate of 3%. what must the principal be if the bank manager also wants to advertise that one can earn $10 the first month? can the poster correctly say, "open an account of $2 comma 500 and earn at least $10 interest in 1 month! "?