If $$x - \frac{1}{x} = 3{\text{,}}$$ then the value of $${x^3} - \frac{1}{{{x^3}}}\,{\text{is?}}$$
A. 32
B. 36
C. 40
D. 49
Answer: Option B
Solution(By Examveda Team)
$$\eqalign{ & x - \frac{1}{x} = 3 \cr & \left( {{\text{By cubing both sides}}} \right) \cr & \Rightarrow {x^3} - \frac{1}{{{x^3}}} - 3.x.\frac{1}{x}\left( {x - \frac{1}{x}} \right) = 27 \cr & \Rightarrow {x^3} - \frac{1}{{{x^3}}} - 3.\left( 3 \right) = 27 \cr & \Rightarrow {x^3} - \frac{1}{{{x^3}}} = 27 + 9 \cr & \Rightarrow {x^3} - \frac{1}{{{x^3}}} = 36 \cr} $$Related Questions on Algebra
If $$p \times q = p + q + \frac{p}{q}{\text{,}}$$ then the value of 8 × 2 is?
A. 6
B. 10
C. 14
D. 16
A. $$1 + \frac{1}{{x + 4}}$$
B. x + 4
C. $$\frac{1}{x}$$
D. $$\frac{{x + 4}}{x}$$
A. $$\frac{{20}}{{27}}$$
B. $$\frac{{27}}{{20}}$$
C. $$\frac{6}{8}$$
D. $$\frac{8}{6}$$
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