Jawabanmu

2014-08-12T20:18:10+07:00
(a+b+c)^2 = a^2+b^2+c^2
(a+b-c)^2 = a^2+b^2-c^2
(a-b+c)^2 = a^2-b^2+c^2
(a-b-c)^2 = a^2-b^2-c^2
2014-08-12T20:19:36+07:00
(a+b+c)^2
= (a+b+c)(a+b+c)
= a^2+ab+ac+ab+b^2+bc+ac+bc+c^2
=a^2+b^2+c^2+2ab+2ac

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