Answer:
198
Step-by-step explanation:
Using the algebraic identity
(a + b)³ = a³ + b³ + 3ab(a + b) , then
with a = x and b = [tex]\frac{1}{x}[/tex]
(x + [tex]\frac{1}{x}[/tex] )³ = x³ + [tex]\frac{1}{x^3}[/tex] + 3 × x × [tex]\frac{1}{x}[/tex] × 6
6³ = x³ + [tex]\frac{1}{x^3}[/tex] + 3 × 6
216 = x³ + [tex]\frac{1}{x^3}[/tex] + 18 ( subtract 18 from both sides )
198 = x³ + [tex]\frac{1}{x^3}[/tex]
