If x = ³√x2 + 11 - 2 , then the value of (x3

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If x = ³√x² + 11 - 2 , then the value of (x³ + 5x² + 12x) is

1. 0
2. 3
3. 7
4. 11

Correct Option: B

x = ³√x² + 11 - 2
⇒ x + 2 = ³√x² + 11
On cubing both sides,
(x + 2)³ = x² + 11
⇒ x³ + 2³ + 3x² × 2 + 3x × 2² = x² + 11
⇒ x³ + 8 + 6x² + 12x = x² + 11
⇒ x³ + 5x² + 12x = 11 – 8 = 3