Mathematics · Cheatsheet
Polynomials & Complex Numbers
Chapter 3 · Solving Systems
📋 Reference · always available
Methods
Substitution or elimination; reduce 3×3 to 2×2.
Unique solution
Lines/planes meet at one point.
No solution
Parallel / inconsistent.
Infinite solutions
Same line/plane (dependent equations).
Methods
Substitution, elimination, or matrices (row reduction). 3 unknowns ⇒ 3 independent equations.
Number of solutions
Unique (lines meet), none (parallel/inconsistent), or infinite (same line/plane).
Common trap
Always check a solution in ALL original equations.