How did I get this wrong?

Write 8(6)/4(3)*2(5) as a single power of 2.

The numbers in brackets are the small numbers at the top. I got 2(7) but my revision book is telling me it's 2(17). What did I do wrong?

4 Answers

Relevance
  • KevinM
    Lv 7
    9 years ago
    Favorite Answer

    If it's written just like that, then the order of operations says you mean:

    (8^6 / 4^3) * 2^5

    = (2^18 / 2^6) * 2^5

    = 2^12 * 2^5

    = 2^17

  • Ashley
    Lv 6
    9 years ago

    this is best done by putting all the values as powers of 2 on the same line

    8^6/4^3*2^5

    = 2^(3•6) / 2^(2•3)•2^5

    = 2^18 / 2^6•2^5

    = 2^18 / 2^11

    = 2^7

    the book has a typo unless it should be

    (2^(3•6) / 2^(2•3))•2^5

    Then the 2^5 belongs in the numerator, and the book is correct

  • Anonymous
    9 years ago

    The small numbers at top are called exponents.

    8^6 / (4^3)(2^5)

    (2*2*2)^6 / (2*2)^3(2^5)

    (2^3)^6 / (2^2)^3(2^5)

    2^(3*6) / 2^(2*3)(2^5)

    2^18 / (2^6)(2^5)

    2^18 / 2^(6+5)

    2^18 / 2^11

    2^(18-11)

    2^7

    Answer: 2^7

    You're correct and your book is wrong.

    ________________________________________________________

    EDIT: It's unclear whether the problem is [(8^6)/(4^3)]*(2^5) with the 2^5 separate from the fraction or if it is (8^6)/[(4^3)(2^5)] with the 2^5 in the denominator.

    [(8^6)/(4^3)]*(2^5)

    = {[(2*2*2)^6]/[(2*2)^3]}*(2^5)

    = {[(2^3)^6]/[(2^2)^3]}*(2^5)

    = {[2^(3*6)]/[2^(2*3)]}*(2^5)

    = [(2^18)/(2^6)]*(2^5)

    = [2^(18-6)]*(2^5)

    = (2^12)*(2^5)

    = 2^(12+5)

    = 2^17

    Next time, use parenthesis to describe it clearly.

  • Anonymous
    9 years ago

    8(15)= 2(3) duh.

    Source(s): a calculator.
Still have questions? Get your answers by asking now.