AlgebraMediumEquation of a line reflected across the x-axis
Algebra practice question
In the xy-plane, the graph of 2x + 3y = 6 is reflected across the x-axis. Which of the following is an equation of the reflected graph?
- A. 2x − 3y = 6Correct
- B. −2x + 3y = 6
- C. 3x + 2y = 6
- D. 2x + 3y = −6
Answer: A. 2x − 3y = 6
Reflecting across the x-axis replaces y with −y: 2x + 3(−y) = 6, or 2x − 3y = 6.
Why the other answers are wrong
- B. −2x + 3y = 6
- −2x + 3y = 6 replaces x with −x, a reflection across the y-axis.
- C. 3x + 2y = 6
- Swapping the coefficients reflects across the line y = x, not the x-axis.
- D. 2x + 3y = −6
- 2x + 3y = −6 reflects through the origin.
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