Guys can someone help it’s systems of equations substitution

How many $20 bills do you need to have to make $280

Express in the simplest form: (x^2+9x+14/x^2-49) / (3x+6/x^2+x-56)

Pepe and leo deposits money into their savings account at the end of the month the table shows the account balances. if there pattern of savings continue and neither earns interest nor withdraw any of the money , how will the balance compare after a very long time ?