0580

Simultaneous Equations

Algebra and Sequences

Two unknowns need two equations

  • A single equation with two unknowns has infinitely many solutions, so a second equation is required to pin them down
  • Simultaneous equations are solved together, and the answer is the pair of values satisfying both at once
The lines 2x − y = 3 and 3x + y = 7 drawn on the same axes, crossing at the single point (2, 1), which is the pair of values that satisfies both equations at once
Source: Linear simultaneous equations by Save My Exams
  • They are linear when neither unknown is squared and the two are not multiplied together
  • Each solution should be checked in the equation that was not used to find it