
The given expression 9x + 24y is equivalent to the expression 3(3x + 8y) because when we distribute the 3 to both terms inside the parentheses, we get 3 multiplied by 3x which is 9x, and 3 multiplied by 8y which is 24y. Therefore, the two expressions are equal. The answer 3(3x + 8y) is the correct one.