Simultaneous equations
Maths · GCSE · The School
To solve 3x + 2y = 16 and x + 2y = 8: the y terms match, so SUBTRACT the equations — 2x = 8, x = 4. Put x back into either equation: 4 + 2y = 8, y = 2. Always substitute into the OTHER equation to check: 3(4) + 2(2) = 16 ✓. If neither variable matches, multiply one equation through first to make a pair match.