Question : If $ x+\frac{1}{x}=3,$ then the value of $x^{5}+\frac{1}{x^{5}}$ is:
Option 1: 110
Option 2: 132
Option 3: 122
Option 4: 123
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Correct Answer: 123
Solution : $x+\frac{1}{x }=3$.........................................(1) Squaring both sides, we get, $⇒(x+\frac{1}{x })^2=3^2$ $⇒x^2+\frac{1}{x^2 } +2=9$ $⇒x^2+\frac{1}{x^2 } =7$..................................(2) Cubing both sides of equation (1), we get, $⇒(x+\frac{1}{x})^3=x^3 + \frac{1}{x^3}+3(x+\frac{1}{x})$ $⇒3^3=x^3 + \frac{1}{x^3}+3(3)$ $⇒x^3 + \frac{1}{x^3}=18$..................................(3) Multiplying (2) and (3), we get, $⇒\left ( x^2+\frac{1}{x^2} \right )\cdot \left ( x^3+\frac{1}{x^3} \right )=7\times 18 = 126$ $⇒x^5+\frac{1}{x^5}+x+\frac{1}{x} = 126$ $⇒x^5+\frac{1}{x^5}+3 = 126$ $\therefore x^5+\frac{1}{x^5} = 123$ Hence, the correct answer is 123.
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Question : If $x+\frac{1}{x}=3$, then the value of $x^5+\frac{1}{x^5}$ is:
Option 1: 322
Option 2: 126
Option 3: 123
Option 4: 113
Question : If $x+\frac{1}{x}=3$, then the value of $\frac{3x^{2}-4x+3}{x^{2}-x+1}$ is:
Option 1: $\frac{4}{3}$
Option 2: $\frac{3}{2}$
Option 3: $\frac{5}{2}$
Option 4: $\frac{5}{3}$
Question : If $x+\frac{1}{x}=0$, then the value of $x^{5}+\frac{1}{x^{5}}$ is:
Option 1: 2
Option 2: –1
Option 3: 1
Option 4: 0
Question : If $x+\frac{1}{x}=2$, then find the value of $x^5+\frac{1}{x^5}$.
Option 1: 1
Option 2: 3
Option 3: 4
Option 4: 2
Question : If $\frac{x}{y}=\frac{4}{5}$, then the value of $(\frac{4}{7}+\frac{2y–x}{2y+x})$ is:
Option 1: $\frac{3}{7}$
Option 2: $1\frac{1}{7}$
Option 3: $1$
Option 4: $2$
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