A company borrowed 400,000 yuan from the bank to produce a new product. It is known that the annual interest rate of the loan is 15% (excluding compound interest, that is, the annual interest rate before the loan is repaid).

Solution: Suppose the bank loan can be repaid in one lump sum after , the tax is 20×4×10%, and the cost is 20×23,000 yuan.

According to the question, we get (20×4 - 20×4×10% - 20×2 . 3) x= 40 (1 + 15 % ×x),

The solution is x= 2,

that is, the bank loan can be paid off in one lump sum after 2 years.

p>