Answer :
Final answer:
The sum of the given polynomials, by combining like terms, is 14x³ −17x² + 9, which corresponds to answer choice c. 14x³ −17x² + 9.
Explanation:
The student has asked for the sum of the given polynomials. To find the sum, we combine like terms, which are terms that have the same variable raised to the same power. The given polynomials are:
(7x³−4x²) + (2x³−4x²) + 5x³−9x² + 9
Combining like terms (terms with x³ and terms with x² separately), we get:
For x³ terms: 7x³ + 2x³ + 5x³ = 14x³
For x² terms: −4x² −4x² −9x² = −17x²
Adding the constant term:
14x³ −17x² + 9
Therefore, the correct sum of the polynomials is 14x³ −17x² + 9, which matches option c. 14x³ −17x² + 9.
