Expand : (a – 2b)^2 - Vidyadip

Question

Expand : $(a – 2b)^2$

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Answer

$(a – 2b)^2 $
$= (a)^2 + (2b)^2− 2 \times a \times 2b ........[(a−b)^2 = a^2 + b^2− 2ab]$
$= a^2+ 4b^2− 4ab$

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