\(1\dfrac{1}{3}.1\dfrac{1}{8}.....1\dfrac{1}{99}\)
\(=\dfrac{4}{3}.\dfrac{9}{8}.....\dfrac{100}{99}\)
\(=\dfrac{2.2}{1.3}.\dfrac{3.3}{2.4}.....\dfrac{10.10}{9.11}\)
\(=\dfrac{2.3.4.....10}{1.2.3.....9}.\dfrac{2.3.4.....10}{3.4.5.....11}\)
\(=10.\dfrac{2}{11}=\dfrac{20}{11}\)
tính nhanh nek mn
\(1\dfrac{1}{3}\times1\dfrac{1}{8}\times1\dfrac{1}{15}\times1\dfrac{1}{24}\times.....\times1\dfrac{1}{99}\)
\(1\frac{1}{2}\times1\frac{1}{3}\times1\frac{1}{4}\times...\times1\frac{1}{2017}\)
\(1\frac{1}{2}\times1\frac{1}{3}\times1\frac{1}{4}\times...\times1\frac{1}{2015}=?\)
1)Tính giá trị biểu thức:
\(C=1\frac{1}{3}\times1\frac{1}{8}\times1\frac{1}{15}\times1\frac{1}{24}\times...\times1\frac{1}{9800}\)
\(E=\frac{11}{1\times3}+\frac{47}{3\times5}+...+\frac{971}{17\times49}\)
2)Tính tổng:
\(A=2+6+12+...+4058210\)
\(B=4+12+24+...+8116420\)
1)So sánh:C với \(4^{100}\div3\)
\(C=1+4+4^2+...+4^{99}\)
Tính tổng: \(1\times1!+2\times2!+3\times3!+....+N\times N!\)
\(\frac{1+\frac{1}{3}+\frac{1}{5}+...+\frac{1}{99}}{\frac{1}{1\times99}+\frac{1}{39\times7}+...+\frac{1}{97\times3}+\frac{1}{99\times1}}\)
\(y=\frac{1\times100+2\times99+3\times98...+99\times2+100\times1}{1\times2+2\times3+3\times4+...+99\times100+100\times101}=?\)
Tính
\(\frac{1+\left(1+2\right)+\left(1+2+3\right)+...+\left(1+2+3+...+99+100\right)}{\left(1\times100+2\times99+3\times98+...+99\times2+100\times1\right)\times2013}\)
\(\dfrac{99}{100}:\left(\dfrac{1}{4}-\dfrac{1}{12}+\dfrac{1}{3}\right)-\left(\dfrac{-7}{5}\right)^2\)
\(\dfrac{13}{15}\cdot0,25\cdot3+\left(\dfrac{8}{15}-1\dfrac{19}{60}\right):1\dfrac{23}{24}\)
\(\frac{5}{2\times1}+\frac{4}{1\times11}+\frac{3}{11\times3}+\frac{1}{2\times15}+\frac{13}{15\times4}\)
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