Question

(2b-9)(2b+9)-4b²........​

Answer 1

Ответ на этот пример -81

Answer 2

To simplify the expression (2b-9)(2b+9)-4b², you can use the distributive property and then combine like terms. Here's how you can do it step by step:

1. Start with the given expression: (2b-9)(2b+9)-4b²

2. Use the distributive property to multiply the terms inside the first parentheses with the terms inside the second parentheses:

   (2b * 2b) + (2b * 9) + (-9 * 2b) + (-9 * 9) - 4b²

3. Simplify each term:

   4b² + 18b - 18b - 81 - 4b²

4. Notice that the terms "18b" and "-18b" cancel each other out, as do "4b²" and "-4b²":

   4b² - 4b² - 81

5. Now, you are left with just the constant term:

   -81

So, the simplified expression is -81.