\(B=\dfrac{3}{2}\times\dfrac{4}{3}\times\dfrac{5}{4}\times...\times\dfrac{100}{99}\)
\(B=\dfrac{3.4.5.....100}{2.3.4.....99}\)
\(B=\dfrac{100}{2}\)
\(B=50\)
BT1: Tính nhanh:
2) ( \(\dfrac{98}{99}+\dfrac{89}{100}+\dfrac{100}{101}\)) . ( \(\dfrac{1}{12}-\dfrac{1}{3}+\dfrac{1}{4}\))
BT1: Tính nhanh:
3) ( \(\dfrac{98}{99}-\dfrac{98}{97}+\dfrac{1}{97.98}\) ) . ( \(\dfrac{1}{2.3}+\dfrac{1}{3.4}+\dfrac{1}{4.5}\))
BT1: Tính nhanh
1) \(\left(\dfrac{-4}{9}+\dfrac{3}{7}\right):1\dfrac{1}{15}+\left(\dfrac{4}{7}-\dfrac{5}{9}\right):1\dfrac{1}{15}\)
2) \(3\dfrac{2}{9}.15\dfrac{4}{7}-3\dfrac{2}{9}.8\dfrac{1}{7}+3\dfrac{2}{9}.\dfrac{15}{7}-3\dfrac{2}{9}.\dfrac{1}{7}\)
BT1: Tính nhanh
3) \(\dfrac{1}{2}-\dfrac{3}{2}.\left(\dfrac{1}{2}-\dfrac{1}{3}\right)+\left(\dfrac{-3}{-2^3}\right)\)
4) \(\dfrac{1}{12}.\dfrac{37}{39}+\dfrac{1}{12}.\dfrac{2}{39}+\dfrac{1}{4}\)
BT1: Tính
4) \(\dfrac{\dfrac{1}{3}-\dfrac{1}{7}-\dfrac{1}{13}}{\dfrac{2}{3}-\dfrac{2}{7}-\dfrac{2}{13}}.\dfrac{\dfrac{3}{4}-\dfrac{3}{16}-\dfrac{3}{64}-\dfrac{3}{264}}{\dfrac{1}{4}-\dfrac{1}{16}-\dfrac{1}{64}-\dfrac{1}{264}}+\dfrac{5}{8}\)
BT1: Tính
3) \(\dfrac{\dfrac{2}{5}+\dfrac{2}{7}-\dfrac{2}{11}}{\dfrac{3}{5}+\dfrac{3}{7}-\dfrac{3}{11}}+\dfrac{\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{7}}{\dfrac{3}{4}-\dfrac{3}{5}+\dfrac{3}{7}}\)
BT1: Tính
1) \(\dfrac{1}{2}-\text{|}\dfrac{1}{5}-\dfrac{1}{4}\text{|}+\left(-\dfrac{1}{3}\right)^2\)
2) \(\dfrac{1}{3}+\dfrac{4}{3}.\left(\dfrac{1}{2}-\dfrac{1}{3}\right)+\left(\dfrac{-2}{3}\right)^2\)
BT1: Tính nhanh:
5) (\(1-\dfrac{1}{5}\)) . ( \(1-\dfrac{2}{5}\)) . ( \(1-\dfrac{3}{5}\)) .... ( \(1-\dfrac{9}{5}\)
BT1: Tính
1) \(3\dfrac{1}{2}+15\dfrac{4}{9}:\dfrac{26}{7}-2\dfrac{4}{9}:\dfrac{26}{7}\)
2) \(34.\left(2\dfrac{1}{17}-3\dfrac{5}{24}\right)+\dfrac{1}{2}\)
