Simultaneous equations - GCSE Maths Definition

Simultaneous equations are a set of equations with multiple variables that are all true at the same time.

In GCSE Mathematics, this will usually be a set of two equations with (the same) two unknowns. x and y are often used for the two unknowns, but other letters can be used, especially where the unknowns are representing a number of objects (a-pples and b-ananas). Simultaneous equations can be solved by (i) eliminating one of the unknown variables; (ii) rearranging and substituting one equation into the other; (iii) finding the intersection of where the graphs of the two equations intersect.