Answer:
123
Step-by-step explanation:
We can square and cube the equation, then multiply the results together.
(a + [tex]\frac{1}{a}[/tex]) = 3 ← square both sides
a² + 2 + [tex]\frac{1}{a^2}[/tex] = 9 ( subtract 2 from both sides )
a² + [tex]\frac{1}{a^2}[/tex] = 7 → (1)
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Now cube both sides
a³ + [tex]\frac{1}{a^3}[/tex] + 3(a + [tex]\frac{1}{a}[/tex]) = 27
a³ + [tex]\frac{1}{a^3}[/tex] + 3(3) = 27
a³ + [tex]\frac{1}{a^3}[/tex] + 9 = 27 ( subtract 9 from both sides )
a³ + [tex]\frac{1}{a^3}[/tex] = 18 → (2)
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Multiply (1) and (2)
(a² + [tex]\frac{1}{a^2}[/tex] )(a³ + [tex]\frac{1}{a^3}[/tex] ) = 7(18)
[tex]a^{5}[/tex] + ( [tex]\frac{1}{a}[/tex] + a) + [tex]\frac{1}{a^5}[/tex] = 126
[tex]a^{5}[/tex] + 3 + [tex]\frac{1}{a^5}[/tex] = 126 ( subtract 3 from both sides )
[tex]a^{5}[/tex] + [tex]\frac{1}{a^5}[/tex] = 123
