Multiple Choice Question (MCQ)

If 8=\dfrac{1}{\dfrac{1}{x^{-3}} } , then x =

  1. ×

    -2.0

  2. ×

    -0.50

  3. ×

    0.50

  4. ×

    1.25

  5. ×

    2.00

Collected in the board: Fractions

Steven Zheng posted 1 month ago


Answer

  1. Multiply x^{-3} with both numerator and denominator, then

    8=\dfrac{1}{\dfrac{1}{x^{-3}} } = \dfrac{1\cdotp x^{-3} }{ \dfrac{1}{x^{-3}}\cdotp x^{-3}} = x^{-3}

    Multiply x^3 with both sides of the equation


    8x^3 = x^{-3}\cdotp x^3 = x^0=1

    Divide both sides with 8

    x^3 = \dfrac{1}{8}

    Then,

    x = \dfrac{1}{2} =0.5



Steven Zheng posted 1 month ago

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