Question

resolva as operaçoes e apresente a resposta na forma reduzida (a+b)2-(a-2b)2

Answer 1

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$(a+b)^2-(a-2b)^2= \\ \\ a^2+2ab+b^2-(a^2-4ab+4b^2) \\ \\ \not a^2+2ab+b^2-\not a^2+4ab-4b^2= \\ \\ 2ab+4ab+b^2-4b^2= \\ \\ 6ab-3b^2$