Final answer:
The expression for Devonte's friend's savings amount is (x^2 - 225). The factored form of the expression is (x + 15)(x - 15).
Step-by-step explanation:
The expression for Devonte's friend's amount can be written as (x^2 - 225). This means that Devonte's friend has 225 less than the square of Devonte's amount in his savings account.
To rewrite the expression in factored form, we can factor out the quadratic expression (x^2 - 225). It can be factored as (x + 15)(x - 15).
So, the factored form of Devonte's friend's amount is (x + 15)(x - 15).