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Home Aptitude Elementary Algebra See What Others Are Saying!
  • Question
  • If a2 + b2 + c2 = 2 (a – b – c) – 3 then the value of 2a – 3b + 4c is


  • Options
  • A. 3
  • B. 1
  • C. 2
  • D. 4

  • Correct Answer


  • Explanation

    As per the given question , we have
    a2 + b2 + c2 = 2 (a – b –c) –3
    ⇒ a2 + b2 + c2 = 2a + 2b + 2c + 3 = 0
    ⇒ a2 – 2a + 1 + b2 + 2b + 1 + c2 + 2c + 1 = 0
    ⇒ (a –1)2 + (b + 1)2 + (c + 1)2 = 0
    [If x2 + y2 + z2 = 0 ⇒ x = 0; y = 0; z = 0]
    ∴ a – 1 = 0 ⇒ a = 1
    b + 1 = 0 ⇒ b = – 1
    c + 1 = 0 ⇒ c = – 1
    ∴ 2a – 3b + 4c = 2 + 3 – 4 = 1


  • More questions

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      If the price of 23 toys is Rs. 276, then what will the price (Rs.) of 12 toys?

    • Options
    • A. 144
    • B. 158
    • C. 159
    • D. 166
    • Discuss
    • 2. 
      .02 =(......?.....)%

    • Options
    • A. 20
    • B. 2
    • C. .02
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    • 3. 
      If 36 men can do a piece of work in 25 hours, in how many hours will 15 men do it?

    • Options
    • A. 45
    • B. 55
    • C. 60
    • D. 72
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    • 4. 
      2?63 / 11 =233

    • Options
    • A. 4
    • B. 3
    • C. 6
    • D. 5
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    • 5. 
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    • Options
    • A. 0
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    • 6. 
      Aarti can do a piece of work in 6 days. In how many days will she complete three time of work of same type?

    • Options
    • A. 18 days
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    • Discuss
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    • Options
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    • 8. 
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    • Options
    • A. 0
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    • 9. 
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    • Options
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    • Discuss
    • 10. 
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    • Options
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