Respuesta :

rijarafiquee

Answer:

15x³ + 5x² - 6x - 7

Step-by-step explanation:

(7x³+5x²-2x+1) + (8x³-4x+4-12)

(7x³ + 5x² - 2x + 1) + (8x³ - 4x + 4 - 12)

7x³ + 5x² - 2x + 1 + 8x³ - 4x + 4 - 12

7x³ + 8x³ + 5x² - 4x - 2x + 1 - 12 + 4

15x³ + 5x² - 6x - 7