Algebra


  1. If  
    x
    =
    y
    =
    z
      , then
    b + cc + aa + b









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    x
    =
    y
    b + cb + a

    =
    x - y
    =
    x - y
    ;
    y
    =
    z
    b + c - c -ab - ac + aa + b

    =
    y - z
    =
    y - z
    ;
    z
    =
    x
    c + a - a - bc - ba + bb + c

    =
    z - x
    =
    z - x
    a + b - b - ca - c

    x - y
    =
    y - z
    =
    z - x
    b - ac - ba - c

    Correct Option: A

    x
    =
    y
    b + cb + a

    =
    x - y
    =
    x - y
    ;
    y
    =
    z
    b + c - c -ab - ac + aa + b

    =
    y - z
    =
    y - z
    ;
    z
    =
    x
    c + a - a - bc - ba + bb + c

    =
    z - x
    =
    z - x
    a + b - b - ca - c

    x - y
    =
    y - z
    =
    z - x
    b - ac - ba - c


  1. If   x = 3 + 2√2 and xy = 1, then the value of
    x2 + 3xy + y2
      is
    x2 − 3xy + y2









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    x = 3 + 2√2
    ⇒ xy = 1

    ⇒ y =
    1
    =
    1
    ×
    3 - 2√2
    3 + 2√23 + 2√23 - 2√2

    =
    3 - 2√2
    = 3 - 2√2
    9 - 8

    ∴ x + y
    = 3 + 2√2 + 3 - 2√2 = 6
    x² + 3xy + y²
    =
    (x + y)² + xy
    x² - 3xy + y²(x - y)² - 5xy

    =
    36 + 1
    =
    37
    36 - 531

    Correct Option: D

    x = 3 + 2√2
    ⇒ xy = 1

    ⇒ y =
    1
    =
    1
    ×
    3 - 2√2
    3 + 2√23 + 2√23 - 2√2

    =
    3 - 2√2
    = 3 - 2√2
    9 - 8

    ∴ x + y
    = 3 + 2√2 + 3 - 2√2 = 6
    x² + 3xy + y²
    =
    (x + y)² + xy
    x² - 3xy + y²(x - y)² - 5xy

    =
    36 + 1
    =
    37
    36 - 531



  1. If   x2 + 5x + 6 = 0, then the value of
    2x
    is :
    x2 − 7x + 6









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    Given,   x2 + 5x + 6 = 0

    ∴  Expression =
    2x
    x2 − 7x + 6

    =
    2x
    =
    2
    x2 + 5x + 6 − 12x −12

    =
    −1
    6

    Correct Option: C

    Given,   x2 + 5x + 6 = 0

    ∴  Expression =
    2x
    x2 − 7x + 6

    =
    2x
    =
    2
    x2 + 5x + 6 − 12x −12

    =
    −1
    6


  1. If  
    a
    +
    b
    +
    c
    =
    1
    , then the value of
    1 − 2a1 − 2b1 − 2c2
    1
    +
    1
    +
    1
    is :
    1 − 2a1 − 2b1 − 2c









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    a
    +
    b
    +
    c
    =
    1
    1 − 2a1 − 2b1 − 2c2

    ⇒ 
    2a
    +
    2b
    +
    2c
    =
    2
    = 1
    1 − 2a1 − 2b1 − 2c2

    ⇒ 
    2a
    + 1 +
    2b
    + 1 +
    2c
    + 1 = 4
    1 − 2a1 − 2b1 − 2c

    ⇒ 
    2a + 1 − 2a
    +
    2b + 1 − 2b
    +
    2c + 1 − 2c
    = 4
    1 − 2a1 − 2b1 − 2c

    ⇒ 
    1
    +
    1
    +
    1
    = 4
    1 − 2a1 − 2b1 − 2c

    Correct Option: D

    a
    +
    b
    +
    c
    =
    1
    1 − 2a1 − 2b1 − 2c2

    ⇒ 
    2a
    +
    2b
    +
    2c
    =
    2
    = 1
    1 − 2a1 − 2b1 − 2c2

    ⇒ 
    2a
    + 1 +
    2b
    + 1 +
    2c
    + 1 = 4
    1 − 2a1 − 2b1 − 2c

    ⇒ 
    2a + 1 − 2a
    +
    2b + 1 − 2b
    +
    2c + 1 − 2c
    = 4
    1 − 2a1 − 2b1 − 2c

    ⇒ 
    1
    +
    1
    +
    1
    = 4
    1 − 2a1 − 2b1 − 2c



  1. If   p2 +
    1
    = 47, the value of p +
    1
    is :
    p2p









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    p2 +
    1
    = 47
    p2

    ⇒  p +
    1
    2 – 2 = 47
    p

    ⇒  p +
    1
    2 = 47 + 2 = 49
    p

    ⇒  p +
    1
    = √49 = 7
    p

    Correct Option: C

    p2 +
    1
    = 47
    p2

    ⇒  p +
    1
    2 – 2 = 47
    p

    ⇒  p +
    1
    2 = 47 + 2 = 49
    p

    ⇒  p +
    1
    = √49 = 7
    p