If $y+\frac{1}{y}=3$, then what is the value of $\frac{1}{y^3}+y^3+2$?
Answer & explanation
Correct answer: option 3
If $y+\frac{1}{y}=3$
what is the value of $\frac{1}{y^3}+y^3+2$
$\frac{1}{y^3}+y^3$ = (y + \(\frac{1}{y}\))3 - 3
$\frac{1}{y^3}+y^3$ = 33 - 3 = 18
$\frac{1}{y^3}+y^3+2$ = 18 + 2 = 20