Question

Difficulty: EasyAlgebraic Exponents and Radicals

If x>1x > 1, which of the following expressions are equivalent to x5x3(x2)1\frac{\sqrt{x^5 \cdot x^3}}{(x^{-2})^{-1}}? Select all such expressions.

  1. (x23)3(x^{\frac{2}{3}})^3Answer
  2. B
    x4+x4\sqrt{x^4 + x^4}
  3. x1x3\frac{x^{-1}}{x^{-3}}Answer
  4. D
    (x1)2x4(x^{-1})^{-2} \cdot x^{-4}
  5. E
    x44\sqrt[4]{x^4}

Answer

The expressions equivalent to the target expression are (x23)3(x^{\frac{2}{3}})^3 and x1x3\frac{x^{-1}}{x^{-3}}.
The original expression simplifies step by step to x2x^2. The expression (x2/3)3(x^{2/3})^3 equals x(2/3)3=x2x^{(2/3)\cdot 3} = x^2, and the expression x1x3\frac{x^{-1}}{x^{-3}} equals x1(3)=x2x^{-1 - (-3)} = x^2. Both are equal to x2x^2.

Step-by-Step Solution

1
Simplify the numerator of the given expression
x5x3=x5+3=x8=x8/2=x4\sqrt{x^5 \cdot x^3} = \sqrt{x^{5+3}} = \sqrt{x^8} = x^{8/2} = x^4
Combine bases using product rule for exponents, then convert radical to fractional exponent.
2
Simplify the denominator of the given expression
(x2)1=x(2)(1)=x2(x^{-2})^{-1} = x^{(-2) \cdot (-1)} = x^2
Multiply exponents when raising a power to a power.
3
Divide the simplified numerator by the simplified denominator
x4x2=x42=x2\frac{x^4}{x^2} = x^{4-2} = x^2
Subtract denominator exponent from numerator exponent using the quotient rule.
4
Evaluate each choice against x2x^2
Only (x2/3)3=x2(x^{2/3})^3 = x^2 and x1x3=x2\frac{x^{-1}}{x^{-3}} = x^2 are equal to x2x^2.
Apply basic exponent rules to each proposed expression.

Key Concept

Algebraic Exponents and Radicals Rules
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