AlgebraMediumConstant shared by two intersecting lines
Algebra practice question
In the xy-plane, the lines y = kx + 2 and y = −kx + 8 intersect at the point (1, 5), where k is a constant. What is the value of k?
Answer: 3
From the first line: 5 = k + 2, so k = 3. Check the second: −3 + 8 = 5. ✓
Common wrong answers
- If you answered 1
- 1 is the x-coordinate.
- If you answered 5
- 5 is the y-coordinate of the intersection.
- If you answered -3
- −3 satisfies neither line at (1, 5).
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