B= (\(\dfrac{2+1}{2}\))\(\times\)\(\left(\dfrac{3+1}{3}\right)\times\left(\dfrac{4+1}{4}\right)\times....\times\left(\dfrac{10+1}{10}\right)\)
B=\(\dfrac{3}{2}\times\dfrac{4}{3}\times...\times\dfrac{11}{10}=\)\(\dfrac{11}{2}\)
\(B=\left(1+\dfrac{1}{2}\right).\left(1+\dfrac{1}{3}\right).\left(1+\dfrac{1}{4}\right)...\left(1+\dfrac{1}{10}\right)\)
\(B=\left(\dfrac{2}{3}+\dfrac{1}{3}\right).\left(\dfrac{3}{3}+\dfrac{1}{3}\right).\left(\dfrac{4}{4}+\dfrac{1}{4}\right)...\left(\dfrac{10}{10}+\dfrac{1}{10}\right)\)
\(B=\dfrac{2+1}{2}.\dfrac{3+1}{3}.\dfrac{4+1}{4}...\dfrac{10+1}{10}\)
\(B=\dfrac{3}{2}.\dfrac{4}{3}.\dfrac{5}{4}...\dfrac{11}{10}\)
\(B=\dfrac{3.4.5...10.11}{2.3.4...10}\)
\(B=\dfrac{11}{10}\)
\(V\)ậ\(y\)\(B=\dfrac{11}{10}\)
