Algebra


  1. If  
    a
    =
    b
    , then value of  
    2a + 3b
      is
    323a − 2b









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    a
    =
    b
    a
    =
    3
    32b2

    ∴ 
    2a + 3b
    3a − 2b
    = 2 ×
    a
    + 3
    b
    3 ×
    a
    − 2
    b
    = 2 ×
    3
    + 3
    2
    3 ×
    3
    − 2
    2
    =
    6
    9 − 4
    2
    =
    12
    5

    Correct Option: A

    a
    =
    b
    a
    =
    3
    32b2

    ∴ 
    2a + 3b
    3a − 2b
    = 2 ×
    a
    + 3
    b
    3 ×
    a
    − 2
    b
    = 2 ×
    3
    + 3
    2
    3 ×
    3
    − 2
    2
    =
    6
    9 − 4
    2
    =
    12
    5


  1. If  
    a
    =
    b
    =
    c
    then
    a + b + c
      is
    equal to
    347c









  1. View Hint View Answer Discuss in Forum

    a
    =
    b
    =
    c
    = k (let)
    347

    a = 3k, b = 4k, c = 7k
    ∴ 
    a + b + c
    =
    3k + 4k + 7k
    c7k

    =
    14k
    = 2
    7k

    Correct Option: C

    a
    =
    b
    =
    c
    = k (let)
    347

    a = 3k, b = 4k, c = 7k
    ∴ 
    a + b + c
    =
    3k + 4k + 7k
    c7k

    =
    14k
    = 2
    7k



  1. If x y = 3x +2y, Then 2 3 + 3 4 is equal to









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    ∵  x * y = 3x + 2y
    2 * 3 + 3 * 4
    = 3 × 2 + 2 × 3 + 3 × 3 + 2 × 4
    = 6 + 6 + 9 + 8 = 29

    Correct Option: B

    ∵  x * y = 3x + 2y
    2 * 3 + 3 * 4
    = 3 × 2 + 2 × 3 + 3 × 3 + 2 × 4
    = 6 + 6 + 9 + 8 = 29


  1. If   x = 7 − 4√3 , then the value of x +
    1
    is :
    x









  1. View Hint View Answer Discuss in Forum

    x = 7 − 4√3

    ∴ 
    1
    =
    1
    x7 − 4√3

    =
    1(7 + 4√3)
    (7 + 4√3)(7 − 4√3)

    =
    7 + 4√3
    = 7 + 4√3
    49 − 48

    ∴  x +
    1
    x

    = 7 − 4√3 + 7 + 4√3 = 14

    Correct Option: D

    x = 7 − 4√3

    ∴ 
    1
    =
    1
    x7 − 4√3

    =
    1(7 + 4√3)
    (7 + 4√3)(7 − 4√3)

    =
    7 + 4√3
    = 7 + 4√3
    49 − 48

    ∴  x +
    1
    x

    = 7 − 4√3 + 7 + 4√3 = 14



  1. If a * b = a + b + ab, then 3 * 4 – 2 * 3 is equal to :









  1. View Hint View Answer Discuss in Forum

    Given a * b = a + b + ab
    ∴  3 * 4 – 2 * 3
    = (3 + 4 + 3 × 4) – (2 + 3 + 2 × 3)
    = (7 + 12) – (5 + 6) = 19 – 11 = 8

    Correct Option: B

    Given a * b = a + b + ab
    ∴  3 * 4 – 2 * 3
    = (3 + 4 + 3 × 4) – (2 + 3 + 2 × 3)
    = (7 + 12) – (5 + 6) = 19 – 11 = 8