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\(\Leftrightarrow\frac{3}{\frac{1.2}{2}}+\frac{3}{\frac{2.3}{2}}+.....+\frac{3}{\frac{100.101}{2}}\)
\(\Leftrightarrow\frac{6}{1.2}+\frac{6}{2.3}+.....+\frac{6}{100.101}\)
\(\Leftrightarrow6\left(\frac{1}{1.2}+\frac{1}{2.3}+.....+\frac{1}{100.101}\right)\)
\(\Leftrightarrow6.\left(\frac{1}{1}-\frac{1}{101}\right)\)
\(\Leftrightarrow6.\frac{100}{101}=\frac{600}{101}\)
Vậy B=\(\frac{600}{101}\)