Question

What is the answer and how do you solve 21x^3/3x^−1

Answer 1

Answer:

  as written: 7x^2

  perhaps intended: 7x^4

Step-by-step explanation:

As written, the Order of Operations specifies that the only denominator factor is 3, so the expression is interpreted as ...

  $\dfrac{21x^3}{3}x^{-1}=\dfrac{21}{3}x^{3-1}=7x^2$

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Sometimes grouping of denominator factors is intended, but parentheses are not written as they should be. If the intention is ...

  21x^3/(3x^-1)

then the simplification is ...

  $\dfrac{21x^3}{3x^{-1}}=\dfrac{21}{3}x^{3-(-1)}=7x^4$

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The applicable rules of exponents are ...

  (a^b)(a^c) = a^(b+c)

  a^b/a^c = a^(b-c)