http://dientuvietnam.net/cgi-bin/mimetex.cgi?\sum{\dfrac{a(3a^{2}b+4\sqrt{3b}+1-3b)}{3(1+a^2)}}-2abc
[TeX]\sum{\dfrac{a(3a^{2}b+4\sqrt{3b}+1-3b)}{3(1+a^2)}}-2abc[/TeX]
[TeX]\sum{\dfrac{a(3a^{2}b+4\sqrt{3b}+1-3b)}{3(1+a^2)}}-2abc[/TeX]
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