Question

Sendo a+ 1/a=3/5. Determine a³+ 1/a³. URGENTE!!

Answer 1

Sabemos que $a+\frac{1}{a}=3/5$

Elevando ao cubo teremos:
$a^{3} + 3a^{2}\frac{1}{a}+3a\frac{1}{a^{2}}+\frac{1}{a^{3}}=27/125$

Dessa forma:
$a^{3} + \frac{1}{a^{3}} + 3(a+\frac{1}{a}) = 27/125$
$a^{3} + \frac{1}{a^{3}} = 27/125 - 9/5 = \frac{-198}{125}$