Example

Simplifying 16x5y754x2y23\sqrt[3]{\frac{16x^5y^7}{54x^2y^2}} and 5a8b680a3b24\sqrt[4]{\frac{5a^8b^6}{80a^3b^2}}

Simplify higher-order roots whose radicands are complex fractions by first reducing the fraction inside the radical, then applying the Quotient Property of nnth Roots.

**ā“‘ 16x5y754x2y23=2xyy233\sqrt[3]{\frac{16x^5y^7}{54x^2y^2}} = \frac{2xy\sqrt[3]{y^2}}{3}: Simplify the fraction inside the radicand: cancel the shared factor of 22 from the coefficients (1654=827\frac{16}{54} = \frac{8}{27}) and apply the Quotient Property for Exponents to the variables (x5x2=x3\frac{x^5}{x^2} = x^3 and y7y2=y5\frac{y^7}{y^2} = y^5). The expression becomes 8x3y5273\sqrt[3]{\frac{8x^3y^5}{27}}. Rewrite using the Quotient Property: 8x3y53273\frac{\sqrt[3]{8x^3y^5}}{\sqrt[3]{27}}. The denominator evaluates cleanly to 33. Simplify the numerator by extracting perfect cube factors: 8x3y33ā‹…y23=2xyy23\sqrt[3]{8x^3y^3} \cdot \sqrt[3]{y^2} = 2xy\sqrt[3]{y^2}. The simplified form is 2xyy233\frac{2xy\sqrt[3]{y^2}}{3}.

ā“’ 5a8b680a3b24=∣ab∣a42\sqrt[4]{\frac{5a^8b^6}{80a^3b^2}} = \frac{|ab|\sqrt[4]{a}}{2}: Simplify the fraction inside the radicand: cancel the shared factor of 55 (580=116\frac{5}{80} = \frac{1}{16}) and simplify the variables (a8a3=a5\frac{a^8}{a^3} = a^5 and b6b2=b4\frac{b^6}{b^2} = b^4). The expression becomes a5b4164\sqrt[4]{\frac{a^5b^4}{16}}. Rewrite using the Quotient Property: a5b44164\frac{\sqrt[4]{a^5b^4}}{\sqrt[4]{16}}. The denominator evaluates to 22. Simplify the numerator by extracting perfect fourth power factors: a4b44ā‹…a4\sqrt[4]{a^4b^4} \cdot \sqrt[4]{a}. Because the index is even, taking the principal fourth root of a4b4a^4b^4 requires absolute value signs: ∣ab∣|ab|. The simplified form is ∣ab∣a42\frac{|ab|\sqrt[4]{a}}{2}.

These examples demonstrate that reducing the fraction under the radical first is crucial — it often reveals numerical and variable perfect powers that allow the expression to be evaluated fully without leaving radicals in the denominator.

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Updated 2026-05-01

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Ch.8 Roots and Radicals - Intermediate Algebra @ OpenStax

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