How do you simpifly algebraic expressions

What is the approximate circumference of the circle shown below?

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?

Michael split a rope that was 28 inches long into 5 equal parts. brenden split a rope that was 30 inches long into 6 equal parts. which boy's rope was cut into longer pieces?