2025 · Q80
The equation x² + px +q = 0 and x² + qx +p = 0 ( p ≠ q ) have a common root. what is the value of (p + q) ?
Elementary MathematicsAlgebra
- A-1
- B0
- C1
- D2
Explanation
Subtracting the equations gives (p−q)α = p−q, so the common root is α = 1 (p ≠ q); then 1 + p + q = 0, i.e. p + q = −1, option (a).