Pair of Linear Equations — Key Conditions
- General pair: a₁x + b₁y + c₁ = 0 and a₂x + b₂y + c₂ = 0
- Unique solution (intersecting lines): a₁/a₂ ≠ b₁/b₂
- No solution (parallel lines): a₁/a₂ = b₁/b₂ ≠ c₁/c₂
- Infinitely many solutions (coincident): a₁/a₂ = b₁/b₂ = c₁/c₂
- Consistent: has at least one solution
- Inconsistent: has no solution
- Methods: substitution, elimination, graphical