Respuesta :

Answer:

(7x³-4x²)+(2x³-4x²) = 7x³-4x²+2x³-4x² = 9x³ - 8x²

Step-by-step explanation:

Answer:

7x - 6x² or    -6x² + 7x

Step-by-step explanation:

(7x-4x²) + (2x²-4x²)

7x - 4x² + 2x² - 4x² = 7x - 8x² + 2x² = 7x - 6x²