What is the result of 3(4 + 5) - 6?

To solve the expression 3(4 + 5) - 6, start by simplifying the expression inside the parentheses first. Calculating 4 + 5 gives you 9. Replacing the parentheses with the sum provides the updated expression: 3(9) - 6.

Next, multiply 3 by 9, which results in 27. Now, you can replace the multiplication in the expression with this value: 27 - 6.

Finally, perform the subtraction. If you subtract 6 from 27, you end up with 21. Therefore, the correct result of the expression is 21.

In the context of the answer choices, 21 is present, confirming it as the correct answer.