Prove the following equalities: a) (a + b)² = a² + 2ab + b² b) (a − b)² = a² − 2ab + b² c) (a + b + c)² = a² + b² + c² + 2ab + 2ac + 2bc d) a² − b² = (a + b)(a − b)
Sign in or create an account to reveal answers, view the solution, and save your progress. Create a free account to unlock practice and keep track of your work.
One puzzle per day. Cryptarithm, Magic Square, Summit. No sign-up required to play.
Play daily puzzle →Interactive problems and curated lessons—water pouring, magic squares, knight's tour, and more.
Browse library →See how you rank. Top solvers by problems solved correctly. Sign in to climb the ranks.
View leaderboard →