Question

Difficulty: MediumAlgebraic Exponents and Radicals

For all x>1x > 1, which of the following expressions is equivalent to x3x23(x1/3)2\frac{\sqrt{x^3 \cdot \sqrt[3]{x^2}}}{(x^{-1/3})^2}?

  1. x5/2x^{5/2}Answer
  2. B
    x7/6x^{7/6}
  3. C
    x5/3x^{5/3}
  4. D
    x13/3x^{13/3}
  5. E
    x35/12x^{35/12}

Answer

x5/2x^{5/2}
Converting all radical expressions into rational exponent form simplifies the numerator to (x11/3)1/2=x11/6(x^{11/3})^{1/2} = x^{11/6} and the denominator to x2/3x^{-2/3}. Applying the quotient rule x11/6/x2/3=x11/6(2/3)x^{11/6} / x^{-2/3} = x^{11/6 - (-2/3)} yields x15/6=x5/2x^{15/6} = x^{5/2}.

Step-by-Step Solution

1
Convert radicals in the numerator to fractional exponents and combine terms inside the square root
x3x23=x3x2/3=x3+2/3=x11/3x^3 \cdot \sqrt[3]{x^2} = x^3 \cdot x^{2/3} = x^{3 + 2/3} = x^{11/3}
When multiplying exponential expressions with the same base, add the exponents.
2
Apply the outer square root to the simplified expression in the numerator
x11/3=(x11/3)1/2=x11/6\sqrt{x^{11/3}} = (x^{11/3})^{1/2} = x^{11/6}
Taking the square root is equivalent to raising an expression to the power of 1/21/2.
3
Simplify the denominator using the power of a power rule
(x1/3)2=x(1/3)2=x2/3(x^{-1/3})^2 = x^{(-1/3) \cdot 2} = x^{-2/3}
When raising a power to another power, multiply the exponents.
4
Divide the simplified numerator by the simplified denominator
x11/6x2/3=x11/6(2/3)=x11/6+4/6=x15/6=x5/2\frac{x^{11/6}}{x^{-2/3}} = x^{11/6 - (-2/3)} = x^{11/6 + 4/6} = x^{15/6} = x^{5/2}
When dividing exponential expressions with the same base, subtract the denominator exponent from the numerator exponent.

Key Concept

Simplifying nested algebraic radicals using rational exponent laws
Estimated Time:1m 30s
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