AlgebraMediumPoint on a line with equal coordinates
Algebra practice question
In the xy-plane, a point on the graph of 3x − 4y = 12 has its x-coordinate equal to its y-coordinate. What is the x-coordinate of that point?
Answer: -12
Set y = x: 3x − 4x = 12 → −x = 12 → x = −12. The point is (−12, −12).
Common wrong answers
- If you answered 4
- 4 is the x-intercept (y = 0), not the point with equal coordinates.
- If you answered 12
- 12 has the wrong sign: 3x − 4x = −x.
- If you answered -3
- −3 is the y-intercept.
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