A Very Nice Math Olympiad Problem | Can You Solve for x? | Algebra | Exponential

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  • เผยแพร่เมื่อ 27 พ.ย. 2024

ความคิดเห็น • 8

  • @1234larry1
    @1234larry1 23 วันที่ผ่านมา

    Although most would simplify to base 2 for the answer, it would be easier to stay in base 4, so that in checking the answer, you eliminate another step. Also, you could have started out when you have (x-2)log4=log3+log5 by simply dividing both sides by log4, eliminating another step.

  • @PopescuVicentiu
    @PopescuVicentiu 12 วันที่ผ่านมา

    I Haven a different solution. Can You check plecase if my solution is corect?
    15=16-1, 15=4^2-4^0, 4^(x-2)=15 =»
    4^x/4^2=4^2-4^0 »
    (2^x)^2=240
    (2^x)=4✓15
    x=log(4✓15), base 2 of log.

  • @thetsukad748
    @thetsukad748 23 วันที่ผ่านมา +1

    I don't think, you should make it so complicated. Use the basic logarithmic identity
    a^log_a(b) = b
    4^(x-2) = 15
    4^(x-2) = 4^log_4(15)
    Bases are equal, therefore powers are also equal
    x - 2 = log_4(15)
    x = log_4(15) + 2

    • @rdfernandes13
      @rdfernandes13 23 วันที่ผ่านมา

      or you could continue calling 2 = log_4(4^2)
      then
      x = log_4(15) + log_4(16)
      x = log_4(240) , then you have the smallest version of the answer

    • @rdfernandes13
      @rdfernandes13 23 วันที่ผ่านมา

      I got to this answer using some others basics
      4^(x-2) = 15 ; log both sides
      (x-2)log4 = log15
      x - 2 = log15/log4 = log_4(15) ; log division let us use divisor as base
      x = log_4(15) + 2
      and then keep as I have before
      calling 2 = log_4(4^2)
      then
      x = log_4(15) + log_4(16)
      x = log_4(240)

  • @key_board_x
    @key_board_x 22 วันที่ผ่านมา

    4^(x - 2) = 15
    Ln[4^(x - 2)] = Ln(15)
    (x - 2).Ln(4) = Ln(15)
    x - 2 = Ln(15) / Ln(4)
    x = 2 + [Ln(15) / Ln(4)]
    x = [2.Ln(4) + Ln(15)] / Ln(4) → to go further
    x = [Ln(4²) + Ln(15)] / Ln(4)
    x = Ln(4² * 15) / Ln(4)
    x = Ln(240) / Ln(4)

  • @prollysine
    @prollysine 22 วันที่ผ่านมา

    4^(x-2)=4^(ln15/ln4) , x-2=ln15/ln4 , x=ln15/ln4+2 , test , 4^(ln15/ln4+2-2)=15 , OK ,

  • @enisogdum1812
    @enisogdum1812 22 วันที่ผ่านมา

    We are just laughing like these questions