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  1. If 6x² – 12x + 1 = 0, then the value of 27x³ +
    1
    is
    8x²
    1. 162
    2. 189
    3. 207
    4. 225
Correct Option: B

6x² – 12x + 1 = 0
Þ 6x² + 1 = 12x

6x² + 1
=
12x
2x2x

⇒ 3x +
1
= 6
2x

On cubing both sides,
3x +
1
³ = (6)³
2x

⇒ (3x)³ +
1
³ = 3 × 3x ×
1
3x +
1
= 216
2x2x2x

⇒ 27x³ +
1
+
9
× 6 = 216
8x³2

⇒ 27x³ +
1
= 216 - 27 = 189
8x³



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