If (3x - 7)3 + (3x - 8)3 + (3x + 6)3 = 3 (3x - 7) (3x - 8) (3x + 6), then what is the value of x?
Show answer & explanation
Correct answer: A
Explanation
Correct Answer is option 1 i.e.1
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Concept |
Understanding |
Application |
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If (a3 + b3 + c3) = 3abc Then (a + b + c) = 0 |
Given (3x – 7)3 + (3x – 8)3 + (3x + 6)3 = 3 (3x – 7) (3x – 8) (3x + 6) If we suppose: (3x – 7) = a (3x – 8) = b (3x + 6) = c |
The equation will turn out to be: (a3 + b3 + c3) = 3abc Then (a + b + c) = 0 Or (3x – 7 + 3x – 8 + 3x + 6) = 0 ⇒ 9x = 9 ⇒ x = 1 |