Practicing Success
If $x - \frac{1}{2x} = 4$, then the value of $8x^3 -\frac{1}{x^3}$ will be : |
540 560 480 520 |
560 |
We know that, If x - y = n then, $x^3 - y^3$ = n3 + 3 × n × xy If $x - \frac{1}{2x} = 4$, x3 - \(\frac{1}{8x^3}\) = 43 + 3 × 4 × \(\frac{1}{2}\) = 70 Multiply the above equation by 8 to get the desired form of result = then the value of $8x^3 -\frac{1}{x^3}$ will be = 70 × 8 = 560 |