Algebra


  1. If m4 +
    1
    = 119 , then m -
    1
    = ?
    m4m










  1. View Hint View Answer Discuss in Forum

    m4 +
    1
    = 119
    m4

    m2 +
    1
    2 - 2 = 119
    m2

    m2 +
    1
    2 = 119 + 2 = 121
    m2

    ⇒ m2 +
    1
    = 11
    m2

    m -
    1
    2 + 2 = 11
    m

    m -
    1
    2 = 11 – 2 = 9
    m

    ⇒ m -
    1
    = ± 3
    m

    Correct Option: A

    m4 +
    1
    = 119
    m4

    m2 +
    1
    2 - 2 = 119
    m2

    m2 +
    1
    2 = 119 + 2 = 121
    m2

    ⇒ m2 +
    1
    = 11
    m2

    m -
    1
    2 + 2 = 11
    m

    m -
    1
    2 = 11 – 2 = 9
    m

    ⇒ m -
    1
    = ± 3
    m


  1. If x -
    1
    = 3 , then the value of x3 -
    1
    is
    xx3










  1. View Hint View Answer Discuss in Forum

    Using Rule 9,

    x -
    1
    = 3
    x

    On cubing both sides,
    x -
    1
    3 = 27
    x

    ⇒ x3 -
    1
    - 3x -
    1
    = 27
    x3x

    ⇒ x3 -
    1
    - 3 × 3 = 27
    x3

    ⇒ x3 -
    1
    = 27 + 9 = 36
    x3

    Correct Option: B

    Using Rule 9,

    x -
    1
    = 3
    x

    On cubing both sides,
    x -
    1
    3 = 27
    x

    ⇒ x3 -
    1
    - 3x -
    1
    = 27
    x3x

    ⇒ x3 -
    1
    - 3 × 3 = 27
    x3

    ⇒ x3 -
    1
    = 27 + 9 = 36
    x3



  1. If x +
    1
    = 3 , then the value of x5 +
    1
    is
    xx5










  1. View Hint View Answer Discuss in Forum

    Using Rule 1 and 8,

    x +
    1
    2 = x2 +
    1
    + 2
    xx2

    ⇒ x2 +
    1
    = 9 - 2 = 7
    x2

    Again ,
    x +
    1
    3 = x3 +
    1
    + 3x +
    1
    xx3x

    ⇒ 27 = x3 +
    1
    + 3 × 3
    x3

    ⇒ x3 +
    1
    = 18
    x3

    x2 +
    1
    x3 +
    1
    = 7 × 18 = 126
    x2x3

    ⇒ x5 + x +
    1
    +
    1
    = 126
    xx5

    ⇒ x5 +
    1
    = 126 – 3 = 123
    x5

    Correct Option: C

    Using Rule 1 and 8,

    x +
    1
    2 = x2 +
    1
    + 2
    xx2

    ⇒ x2 +
    1
    = 9 - 2 = 7
    x2

    Again ,
    x +
    1
    3 = x3 +
    1
    + 3x +
    1
    xx3x

    ⇒ 27 = x3 +
    1
    + 3 × 3
    x3

    ⇒ x3 +
    1
    = 18
    x3

    x2 +
    1
    x3 +
    1
    = 7 × 18 = 126
    x2x3

    ⇒ x5 + x +
    1
    +
    1
    = 126
    xx5

    ⇒ x5 +
    1
    = 126 – 3 = 123
    x5


  1. If x is real, x +
    1
    ≠ 0 and x3 +
    1
    = 0 , then the value of x +
    1
    4 is
    xx3x









  1. View Hint View Answer Discuss in Forum

    Using Rule 8

    x +
    1
    3 = x3 +
    1
    + 3x +
    1
    xx3x

    = 3x +
    1
    x

    x +
    1
    2 = 3
    x

    x +
    1
    4 = 3 × 3 = 9
    x

    Correct Option: B

    Using Rule 8

    x +
    1
    3 = x3 +
    1
    + 3x +
    1
    xx3x

    = 3x +
    1
    x

    x +
    1
    2 = 3
    x

    x +
    1
    4 = 3 × 3 = 9
    x



  1. If x +
    1
    = 5 , then the value of
    x4 + 3x3 + 5x2 + 3x + 1
    xx4 + 1









  1. View Hint View Answer Discuss in Forum

    Using Rule1 and 8,

    ⇒ x +
    1
    = 5
    x

    On squaring both sides,
    ⇒ x2 +
    1
    + 2 = 25
    x2

    ⇒ x2 +
    1
    = 25 - 2 = 23 ...(i)
    x2

    Expression
    =
    x4 + 3x3 + 5x2 + 3x + 1
    x4 + 1

    =
    x4 + 1 + 3x3 + 3x + 5x2
    x4 + 1


    =
    23 + 3 × 5 + 5
    =
    43
    2323

    Correct Option: A

    Using Rule1 and 8,

    ⇒ x +
    1
    = 5
    x

    On squaring both sides,
    ⇒ x2 +
    1
    + 2 = 25
    x2

    ⇒ x2 +
    1
    = 25 - 2 = 23 ...(i)
    x2

    Expression
    =
    x4 + 3x3 + 5x2 + 3x + 1
    x4 + 1

    =
    x4 + 1 + 3x3 + 3x + 5x2
    x4 + 1


    =
    23 + 3 × 5 + 5
    =
    43
    2323