Binomial formulas (Year 7)

The three binomial formulas: (a + b)² = a² + 2ab + b², (a − b)² = a² − 2ab + b² and (a + b)(a − b) = a² − b². Exercises live under the German Klasse 7 (binomische Formeln are an explicit KMK Klasse 7 requirement); EN gets an introduction article only — UK/US curricula treat binomial expansions in Year 8/9.