1. Fundamental Concepts
- Definition: The general form of a quadratic equation is (). When the independent term (constant term) , the equation simplifies to .
- Core Feature: The equation contains no constant term, and all terms include the variable x. Thus, it can be solved by factoring out the common factor.
2. Key Concepts
- Simplified Equation Form: (, , ).
- Solution Principle: By factoring out the common factor x, the equation is transformed into . Using the property that "if the product of two factors is 0, at least one of the factors must be 0," we get:
- or
- Solving these gives two roots: and .
- Characteristic of Roots: One root is always , and the other root is determined by the coefficients of the linear term and the quadratic term.
3. Examples
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Easy: Solve the equation
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Solution: Factor out the common factor x, resulting in .Then or , so and .
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Medium: Solve the equation
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Solution: Factor out the common factor 3x, resulting in .Then or , so and .
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Hard: Solve the equation
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Solution: Factor out the common factor , resulting in .Then or , so and .
4. Problem-Solving Techniques
- Identify the Equation Type: Confirm that the constant term in the quadratic equation, i.e., the equation is in the form .
- Factor Out the Common Factor: Extract the common factor containing x to transform the equation into the product form .
- Solve for Each Factor: Set each factor equal to 0 separately and solve for the two roots (one of which is always 0).
- Verify the Results (optional): Substitute the solutions back into the original equation to check if they satisfy the equality (to ensure correctness).