How can we remove negative tiles when the collection has only positive tiles?

Select the lengths in centimeters that would form a right triangle

Bring the fraction a/a-4 to a denominator of 16-a^2

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?