Practicing Success
If x = 555, y = 556 and z = 557, then the value of $x^3 + y^3 + z^3 - 3xyz$. |
5006 5002 5008 5004 |
5004 |
If x = 555 y = 556 z = 557 then the value of $x^3 + y^3 + z^3 - 3xyz$ = ? x3 + y3 + z3 – 3xyz = \(\frac{1}{2}\) (x + y + z) [(x – y)2 + (y – z)2 + (z – x)2 x3 + y3 + z3 – 3xyz = \(\frac{1}{2}\) (555 + 556 + 557)[(555 – 556)2 + (556 – 557)2 + (557 – 555)2] x3 + y3 + z3 – 3xyz = \(\frac{1}{2}\) × 1668 [(-1)2 + (-1)2 + (2)2] x3 + y3 + z3 – 3xyz = 834 × (1 + 1 + 4) x3 + y3 + z3 – 3xyz = 834 × 6 x3 + y3 + z3 – 3xyz = 5004 |