Question 337140
Choose the correct simplification of (2x^3 + x^2 − 4x) − (9x^3 − 3x^2).
I think the answer is A but im not so sure 
A: 11x^3 − 2x^2 − 4x 
B: −7x^3 + 4x^2 − 4x
C: −2x^3 − 2x^2 − 4x 
D: −7x^3 − 4x^2 − 4x



(2x^3 + x^2 - 4x) - (9x^3 - 3x^2)
2x^3 + x^2 - 4x - 9x^3 + 3x^2 (distributed the -1 into the last 2 terms)
2x^3 - 9x^3 + x^2 + 3x^2 - 4x (grouped like terms together)
-7x^3 + 4x^2 - 4x (simplified)


the answer is not A, it is B