Multi Fraction Simplifications
1. Simplify \(\frac{4-\frac{9}{x^2}}{2-\frac{3}{x}}\).
Rewrite numerator: \(4-\frac{9}{x^2} = \frac{4x^2 - 9}{x^2} = \frac{(2x - 3)(2x + 3)}{x^2}\).
Rewrite denominator: \(2-\frac{3}{x} = \frac{2x - 3}{x}\).
Divide numerator by denominator:
$$\frac{\frac{(2x - 3)(2x + 3)}{x^2}}{\frac{2x - 3}{x}} = \frac{(2x - 3)(2x + 3)}{x^2} \times \frac{x}{2x - 3} = \frac{2x + 3}{x} = 2 + \frac{3}{x}.$$
Answer: (a) \(2 + \frac{3}{x}\).
2. Simplify \(\frac{\frac{1}{x} - \frac{1}{y}}{x - y}\).
The numerator: \(\frac{1}{x} - \frac{1}{y} = \frac{y - x}{xy} = -\frac{x - y}{xy}\).
Divide by \(x-y\):
$$\frac{-\frac{x - y}{xy}}{x - y} = -\frac{x - y}{xy} \times \frac{1}{x - y} = -\frac{1}{xy}.$$
Answer: (a) \(-\frac{1}{xy}\).
3. Simplify \(\frac{\frac{x}{y} - \frac{y}{x}}{\frac{1}{y} - \frac{1}{x}}\).
Numerator: \(\frac{x}{y} - \frac{y}{x} = \frac{x^2 - y^2}{xy} = \frac{(x - y)(x + y)}{xy}\).
Denominator: \(\frac{1}{y} - \frac{1}{x} = \frac{x - y}{xy}\).
Divide:
$$\frac{\frac{(x - y)(x + y)}{xy}}{\frac{x - y}{xy}} = \frac{(x - y)(x + y)}{xy} \times \frac{xy}{x - y} = x + y.$$
Answer: (b) \(x + y\).
4. Simplify \(\frac{\frac{x^2 - y^2}{xy}}{\frac{3}{x} - \frac{3}{y}}\).
Numerator: \(\frac{x^2 - y^2}{xy} = \frac{(x - y)(x + y)}{xy}\).
Denominator: \(\frac{3}{x} - \frac{3}{y} = 3\left(\frac{1}{x} - \frac{1}{y}\right) = 3 \frac{y - x}{xy} = -3 \frac{x - y}{xy}\).
Divide:
$$\frac{\frac{(x - y)(x + y)}{xy}}{-3 \frac{x - y}{xy}} = \frac{(x - y)(x + y)}{xy} \times \frac{xy}{-3(x - y)} = -\frac{x + y}{3}.$$
No answer matches exactly among choices (a), (b), (c), answer is (d) none.
5. Simplify \(\sqrt[3]{9x^5y^2} \cdot \sqrt[3]{9z^5} = \sqrt[3]{81 x^5 y^2 z^5}\).
Since \(81 = 3^4\), rewrite inside cube root: \(3^4 x^{5} y^{2} z^{5} = 3^3 \times 3 x^{3} x^{2} y^{2} z^{3} z^{2}\).
Separate perfect cubes:
$$3^3 x^3 z^3 \times 3 x^2 y^2 z^2 = (3 x z)^3 \times 3 x^2 y^2 z^2.$$
Take cube root:
$$3 x z \sqrt[3]{3 x^{2} y^{2} z^{2}}.$$
Answer: (c) \(3 x z \sqrt[3]{3 x^{2} y^{2} z^{2}}\).
6. Simplify \(\sqrt[4]{32 x^{15} y^{11}}\).
Prime factors: \(32 = 2^{5}\), so inside is \(2^{5} x^{15} y^{11}\).
Rewrite exponents in multiples of 4 plus remainder:
\(2^{5} = 2^{4} \times 2^{1}\), \(x^{15} = x^{12} \times x^{3}\), \(y^{11} = y^{8} \times y^{3}\).
Extract fourth roots:
$$2^{4/4} x^{12/4} y^{8/4} \sqrt[4]{2^{1} x^{3} y^{3}} = 2 x^{3} y^{2} \sqrt[4]{2 x^{3} y^{3}}.$$
Answer: (c) \(2 x^{3} y^{2} \sqrt[4]{2 x^{3} y^{3}}\).
7. Simplify \(\frac{27 x^3 y^2}{\sqrt{9 x y}}\).
Since \(\sqrt{9 x y} = 3 \sqrt{x y}\), write denominator as \(3 \sqrt{x y}\).
Divide:
$$\frac{27 x^3 y^2}{3 \sqrt{x y}} = 9 x^{3} y^{2} \frac{1}{\sqrt{x y}} = 9 x^{3} y^{2} \times (x y)^{-1/2} = 9 x^{3 - 1/2} y^{2 - 1/2} = 9 x^{5/2} y^{3/2}.$$
Express \(y^{3/2} = y \sqrt{y}\) to match answer:
$$9 x^{5/2} y \sqrt{y} = 9 x^{5/2} y \sqrt{y}$$
Answer matches (a) \(9 x^{5/2} y\) only if ignoring \(\sqrt{y}\) factor, so no exact match. Check (b): \(9 x^{2} y \sqrt{x y} = 9 x^{2} y \sqrt{x y}\) expands as
$$9 x^{2} y x^{1/2} y^{1/2} = 9 x^{2.5} y^{1.5} = 9 x^{5/2} y^{3/2},$$ perfect match.
Answer: (b) \(9 x^{2} y \sqrt{x y}\).
8. Simplify \(\frac{\sqrt[3]{x^{4} y^{5}}}{\sqrt[3]{x y^{2}}}\).
Divide inside cube roots:
$$\sqrt[3]{\frac{x^{4} y^{5}}{x y^{2}}} = \sqrt[3]{x^{3} y^{3}} = \sqrt[3]{(x y)^3} = x y.$$
Answer: (a) \(x y\).
9. Simplify \(\sqrt[3]{256 x^{5}} - \sqrt[3]{4 x^{5}}\).
Rewrite:
$$256 = 2^{8}, \ 4 = 2^{2}.$$
So:
$$\sqrt[3]{2^{8} x^{5}} - \sqrt[3]{2^{2} x^{5}} = 2^{8/3} x^{5/3} - 2^{2/3} x^{5/3} = x^{5/3} (2^{8/3} - 2^{2/3}) = x^{5/3} 2^{2/3} (2^{2} - 1).$$
Calculate \(2^{2} - 1 = 4 - 1 = 3\), so expression is
$$3 \cdot 2^{2/3} x^{5/3} = 3 x^{5/3} \sqrt[3]{4}.$$
No options given, final simplified form is above.
"q_count":9