Answer: Two parallel lines.
- A Two parallel lines
- B Two perpendicular lines
- C Two lines at 45°
- D Two coincident lines
Correct answer: A. Two parallel lines
Explanation: 2x² + 5xy + 2y² = (2x+y)(x+2y) = 0. The two lines: y = -2x and y = -x/2. Slopes -2 and -1/2, product = 1... not perpendicular. They are distinct lines.
The slope of a line is the ratio of vertical change (rise) to horizontal change (run) between any two points on it - equivalently, the tangent of the angle θ the line makes with the positive x-axis.