Answer: y = x.
- A y = x
- B x = 5
- C y = 5
- D x + y = 0
Correct answer: A. y = x
Explanation: Line x + y = 5 has slope -1. Perpendicular slope = 1. Line through origin: y = x.
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.