Algebra


  1. If p = 101, then the value of ³√p( p² - 3p + 3 ) - 1 is









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    Using Rule 9,
    Expression = ³√p( p² - 3p + 3 ) - 1
    Expression = ³√( p³ - 3p² + 3p - 1
    Expression = ³√(p - 1)³ = p - 1
    Expression = 101 – 1 = 100

    Correct Option: A

    Using Rule 9,
    Expression = ³√p( p² - 3p + 3 ) - 1
    Expression = ³√( p³ - 3p² + 3p - 1
    Expression = ³√(p - 1)³ = p - 1
    Expression = 101 – 1 = 100


  1. If p = 124, ³√p( p² + 3p + 3 ) + 1 is









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    Using Rule 8,
    Expression = ³√p( p² + 3p + 3 ) + 1
    Expression = ³√( p³ + 3p² + 3p + 1
    Expression = ³√(p + 1)³ = [ ( p + 1 )³ ]1 / 3 = ( p + 1 )
    When p = 124,
    Expression = p + 1 = 124 + 1 = 125

    Correct Option: D

    Using Rule 8,
    Expression = ³√p( p² + 3p + 3 ) + 1
    Expression = ³√( p³ + 3p² + 3p + 1
    Expression = ³√(p + 1)³ = [ ( p + 1 )³ ]1 / 3 = ( p + 1 )
    When p = 124,
    Expression = p + 1 = 124 + 1 = 125



  1. If p – 2q = 4, then the value of p³ – 8q³ – 24pq – 64 is :









  1. View Hint View Answer Discuss in Forum

    Using Rule 9,
    p – 2q = 4
    On cubing both sides,
    (p – 2q)3 = 64
    ⇒ p3 - 8q3 + 3p.4q2 - 3p2.2q = 64
    ⇒ p3 - 8q3 + 12pq2 - 6p2q = 64
    ⇒ p3 - 8q3 + 6pq(p – 2q) = 64
    ⇒ p3 - 8q3 + 6pq × 4 = 64
    ⇒ p3 - 8q3 – 24pq – 64 = 0

    Correct Option: B

    Using Rule 9,
    p – 2q = 4
    On cubing both sides,
    (p – 2q)3 = 64
    ⇒ p3 - 8q3 + 3p.4q2 - 3p2.2q = 64
    ⇒ p3 - 8q3 + 12pq2 - 6p2q = 64
    ⇒ p3 - 8q3 + 6pq(p – 2q) = 64
    ⇒ p3 - 8q3 + 6pq × 4 = 64
    ⇒ p3 - 8q3 – 24pq – 64 = 0


  1. If x = 19 and y = 18, then the value of
    x2 + y2 + xy
    is :
    x3 - y3










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    Expression =
    x2 + y2 + xy
    x3 - y3

    Expression =
    x2 + y2 + xy
    =
    1
    (x - y)(x2 + y2 + xy)(x - y)

    Expression =
    1
    = 1
    19 - 18

    Correct Option: A

    Expression =
    x2 + y2 + xy
    x3 - y3

    Expression =
    x2 + y2 + xy
    =
    1
    (x - y)(x2 + y2 + xy)(x - y)

    Expression =
    1
    = 1
    19 - 18



  1. If x +
    1
    = 2 and x is real, then the value of x17 +
    1
    is
    xx19










  1. View Hint View Answer Discuss in Forum

    x +
    1
    = 2
    x

    ⇒ x2 - 2x + 1 = 0
    ⇒ ( x - 1 )2 = 0 ⇒ x = 1
    ∴ x17 +
    1
    = 1 + 1 = 2
    x19

    Second Method :-
    Here, x +
    1
    = 2
    x

    By Hit and trial method , putting x = 1
    ∴ x17 +
    1
    = 2
    x19

    Correct Option: C

    x +
    1
    = 2
    x

    ⇒ x2 - 2x + 1 = 0
    ⇒ ( x - 1 )2 = 0 ⇒ x = 1
    ∴ x17 +
    1
    = 1 + 1 = 2
    x19

    Second Method :-
    Here, x +
    1
    = 2
    x

    By Hit and trial method , putting x = 1
    ∴ x17 +
    1
    = 2
    x19