Please help me I need it

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36

Two angles are complementary. the larger angle is 36 more than the smaller angle. what is the measure of the larger angle?

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?