Difficulty: Medium
Correct Answer: 2, 6
Explanation:
Introduction / Context:
Equalizing three expressions to a common parameter is a common technique. Assign a parameter t to the shared value, convert each proportional statement into a linear equation, and then solve the resulting system for x and y efficiently.
Given Data / Assumptions:
Concept / Approach:
Let each fraction equal t. Then x + y − 8 = 2t, x + 2y − 14 = 3t, and 3x + y − 12 = 11t. Eliminate t by equating suitable pairs, reducing the problem to two linear equations in x and y.
Step-by-Step Solution:
Verification / Alternative check:
Compute t: (x + y − 8)/2 = (2 + 6 − 8)/2 = 0; the other two also evaluate to 0. All three equal, confirming correctness.
Why Other Options Are Wrong:
Other pairs do not satisfy all three equalities simultaneously when substituted back.
Common Pitfalls:
Dropping constants during cross-multiplication or equating only two of the three expressions without checking the third one for consistency.
Final Answer:
2, 6
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