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Question
Expand the following:
(4a – b + 2c)2
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Solution
(4a – b + 2c)2
= (4a)2 + (–b)2 + (2c)2 + 2(4a)(–b) + 2(–b)(2c) + 2(2c)(4a) ...[Using identity, (a + b + c)2 = a2 + b2 + c2 + 2ab + 2bc + 2ca]
= 16a2 + b2 + 4c2 – 8ab – 4bc + 16ac
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