Answer:
B. x3 + 4x2 − x + 3
Step-by-step explanation:
(−7x^3 + 5x^2 − x + 6) − (−8x^3 + x^2 + 3)
Distribute the negative sign
(−7x^3 + 5x^2 − x + 6) + (8x^3 - x^2 - 3)
I like to line them up vertically.
−7x^3 + 5x^2 − x + 6
8x^3 - x^2 - 3
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x^3 +4x^2 -x +3