Final answer:
By adding the coefficients of -16a⁵ and -17a⁵, the expression simplifies to -33a⁵, which is answer choice (a).
Step-by-step explanation:
The question requires us to simplify the expression by combining like terms. Since both terms in the expression, -16a⁵ and -17a⁵, have the same variable part raised to the same power, we can combine them by adding the coefficients (the numbers in front of the variable part).
-16a⁵ - 17a⁵ = -33a⁵
Thus, after combining the coefficients, the expression simplifies to -33a⁵, aligning with answer choice (a) -33a⁵, showcasing the process of combining like terms by adding their coefficients in expressions with similar variables and exponents.