6*. Разложите на множители: 25a²-(a+3)²

Using the difference of squares formula (A² - B² = (A - B)(A + B)), where A = 5a and B = (a+3): (5a - (a+3))(5a + (a+3)) = (5a - a - 3)(5a + a + 3) = (4a - 3)(6a + 3)