Difficulty: Easy
Correct Answer: 5
Explanation:
Introduction / Context:
This problem directly uses a well-known algebraic identity. When x + y + z ≠ 0, the expression (x^3 + y^3 + z^3 - 3xyz) / (x^2 + y^2 + z^2 - xy - yz - zx) simplifies elegantly to x + y + z.
Given Data / Assumptions:
Concept / Approach:
Use the identity: (x^3 + y^3 + z^3 - 3xyz) / (x^2 + y^2 + z^2 - xy - yz - zx) = x + y + z, provided x + y + z ≠ 0. Here, the numbers are chosen so their sum is exact and simple.
Step-by-Step Solution:
Verification / Alternative check:
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Discussion & Comments