For which of the following positive integers is the square o
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21 Feb 2024, 22:34
Translating the words to mathematical representation we get
\(\frac{x^2}{\sqrt[3]{x}} = 9x\)
\(x^2 = 9x \sqrt[3]{x}\)
\(x^2 = 9x \times x^{\frac{1}{3}}\)
\(x^2 = 9 \times x^{\frac{4}{3}}\)
\(x^2 = 9({x^\frac{2}{3}}^2)\)
\(x^2 = 3^2 \times ({x^\frac{2}{3}}^2)\)
Taking the square root on both sides, we get
\(x = 3 \times x^{\frac{2}{3}}\)
rearranging the terms
\(x \times x^{\frac{-2}{3}} = 3\)
\(x^{\frac{1}{3}} = 3\)
cubing both sides to get the value of \(x\) on the LHS
\(x = 3^3\)
\(x=27\)
The answer is D