The tens digit of a two digit number is twice the units digit. if the digits are reversed, the new number is 36 less than the original number. find the number.

At the beginning of year 1, carlos invests $600 at an annual compound interest rate of 4%. he makes no deposits to or withdrawals from the account. which explicit formula can be used to find the account's balance at the beginning of year 5? what is, the balance?