Difficulty: Easy
Correct Answer: no solution
Explanation:
Introduction / Context:
This problem examines whether two linear equations represent the same line, different parallel lines, or intersecting lines. Comparing proportional coefficients provides a quick test for consistency or inconsistency of the system.
Given Data / Assumptions:
Concept / Approach:
If the left-hand sides are proportional but the constants are not in the same ratio, the lines are parallel and distinct, producing no solution. Multiply E1 by 2 to compare fairly with E2.
Step-by-Step Solution:
Verification / Alternative check:
Graphically, both lines have slope −(2/4) = −1/2, but different intercepts; hence they never meet.
Why Other Options Are Wrong:
Unique or infinite solutions would require equality of constants after scaling; “exactly two solutions” is not a concept in linear pairs in the plane.
Common Pitfalls:
Stopping after noticing proportional coefficients and not checking constants, which changes the conclusion from coincident to parallel lines.
Final Answer:
no solution
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