The correct answer is (D) -2x - 8.
To simplify the expression -1/3 ( 6x + 15 ) - 3, we can first apply the distributive property to the term in parentheses:
-1/3 ( 6x + 15 ) - 3 = -1/3 * 6x - 1/3 * 15 - 3
Then we can simplify using the properties of multiplication and division:
-1/3 * 6x - 1/3 * 15 - 3 = -2x - 5 - 3
Finally, we can combine like terms:
-2x - 5 - 3 = -2x - 8
The correct answer is therefore (D) -2x - 8.✅