Answer:
C.
Step-by-step explanation:

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Answer: x = 4
Step-by-step explanation:
The cube root of 64 is 4
Answer: -30, -10, 15, 20
Step-by-step explanation:
You start off by multiplying the second bracket by -1 to get rid of the bracket.
So,
(2x3 + x2 - 4x) - 9x3 + 3x2 =
2x3 +x2 - 4x - 9x3 + 3x2 =
(2x3 - 9x3) + (x2 + 3x2) - 4x =
-7x3 + 4x2 - 4x