If y = 4x, what is y if the x = 5?

Aportion of a line bounded by two points is defined as

The difference of two numbers is 40. find the numbers if 0.3 parts of one number is equal to 37.5% of the other one.

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?