If X + 1/2x= 3, then evaluate 8x^3 +1/(x^3).

If $ X + \frac{1}{2x}= 3,$

Then, $8x^3 +\frac{1}{x^3}$ = ?

Multiply the equation with 2 = 2 ($ X + \frac{1}{2x}= 3,$)

=$ 2X + \frac{1}{x}= 6,$

$8x^3 +\frac{1}{x^3}$ = 6³ - 3 × 6 × 2 = 180