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Alsina, C. and Monreal, A. 2003. Proof without words: (a + b)^3 = a^3 +3a^2b +3ab^2 + b^3. Teaching Mathematics and Computer Science. 1, 1 (Jun. 2003), 157. DOI:https://doi.org/10.5485/TMCS.2003.0004.