Simultaneous equations in three unknowns (AQA GCSE Further Maths): Flashcards

Exactly three separate equations

$x$, $y$, and $z$

Choose a variable; eliminate it from two equations

Eliminate same variable from different pair of equations

Solve the two-variable system

Substitute back to find third variable

Must eliminate the same variable in both steps

Rearrange them first before applying elimination

Label equations clearly and number your steps

Pick one with matching coefficients or simple multiples

Substitute answers back into all three original equations

Elimination method (or four-step elimination method)