vì 1/27^11 = 1/(3^3)^11 = 1/3^33
1/81^8= 1/(9^2)^8 = 1/9^16 = 1/(3^2)^16 = 1/3^32
=> <
vì 1/3^99= 1/(3)^33.3=1/99^3 = 1/ (33.3)^3 = 1/33^9
1/11^21=1/(11)^3.7=1/33^7
=> " > "
nhớ ****
\(A=\frac{\frac{1}{11}-\frac{1}{13}-\frac{1}{17}}{\frac{5}{11}-\frac{5}{13}-\frac{5}{17}}+\frac{\frac{-3}{3}-\frac{2}{9}-\frac{2}{27}+\frac{2}{81}}{\frac{7}{3}-\frac{7}{9}-\frac{7}{27}+\frac{7}{81}}\)
a.\(\frac{27}{12}+\frac{5}{21}-\frac{4}{23}+\frac{6}{21}+\frac{1}{2}\)
b.\(\frac{1}{2}+(-\frac{1}{7})-(\frac{-1}{13})+\frac{-1}{3}-(\frac{-2}{5})+\frac{-11}{21}+\frac{1}{10}\)
Cho B=\(\left(1-\frac{1}{4}\right).\left(1-\frac{1}{9}\right).\left(1-\frac{1}{16}\right)...\left(1-\frac{1}{81}\right).\left(1-\frac{1}{100}\right)\)
So sánh B với 11/21
Bài 1 : cho 2 biểu thức
\(A=\left(1-\frac{1}{2}\right)\left(1-\frac{1}{3}\right)...\left(1-\frac{1}{19}\right)\left(1-\frac{1}{20}\right)\)
\(B=\left(1-\frac{1}{4}\right)\left(1-\frac{1}{9}\right)\left(1-\frac{1}{16}\right)...\left(1-\frac{1}{81}\right)\left(1-\frac{1}{100}\right)\)
So sánh A với \(\frac{1}{21}\)
So sánh B với \(\frac{11}{21}\)
A=\(\frac{3^3}{1}-\frac{5^3}{3}+\frac{7^3}{6}-\frac{9^3}{10}+\frac{11^3}{15}-\frac{13^3}{21}+...+\frac{1993^3}{4950}\). So sánh A và B=814
Tính giá trị biểu thức
\(1.A=\frac{1}{5}+\frac{3}{17}-\frac{4}{3}+\left(\frac{4}{5}-\frac{3}{17}+\frac{1}{3}\right)-\frac{1}{7}+\left[\frac{-14}{30}\right]\)
\(2.B=\left(\frac{5}{8}-\frac{4}{12}+\frac{3}{2}\right)-\left(\frac{5}{8}+\frac{9}{13}\right)-\left[\frac{-3}{2}\right]+\frac{7}{-15}\)
\(3.C=\frac{5}{18}+\frac{8}{19}-\frac{7}{21}+\left(\frac{-10}{36}+\frac{11}{19}+\frac{1}{3}\right)-\frac{5}{8}\)
\(4.D=\frac{1}{9}-\left[\frac{-5}{23}\right]-\left(\frac{-5}{23}+\frac{1}{9}+\frac{25}{7}\right)+\frac{50}{14}-\frac{7}{30}\)
\(5.E=\frac{1}{13}+\left(\frac{-5}{18}-\frac{1}{13}+\frac{12}{17}\right)+\left(\frac{12}{17}+\frac{5}{18}+\frac{7}{5}\right)\)
\(6.F=\frac{15}{14}-\left(\frac{17}{23}-\frac{80}{87}+\frac{5}{4}\right)+\left(\frac{12}{17}-\frac{15}{14}+\frac{1}{4}\right)\)
\(7.G=\frac{1}{25}-\frac{4}{27}+\left(\frac{-23}{27}+\frac{-1}{25}-\frac{5}{43}\right)+\frac{5}{43}-\frac{4}{7}\)
\(8.H=\frac{4}{15}-\frac{23}{28}-\left(\frac{-23}{28}+\frac{-11}{15}-\frac{29}{27}\right)-\frac{2}{27}\)
\(9.K=\frac{1}{16}-\frac{5}{21}+\left(\frac{-1}{16}+\frac{-3}{5}-\frac{-5}{21}\right)+\frac{-2}{5}+\frac{3}{4}\)
\(10.L=\frac{7}{12}+\frac{15}{14}-\left(\frac{14}{22}+\frac{-1}{14}+\frac{5}{21}\right)-\frac{-5}{21}+\frac{3}{5}\)
so sánh:a,3^99 và 11^21 b,Cho A=3^1+3^2+...+3^100.CMR:A chia hết cho 40
Cho \(P=\frac{\frac{1}{99}+\frac{2}{98}+\frac{3}{97}+..+\frac{99}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+..+\frac{1}{100}}\)và \(Q=\frac{92-\frac{1}{9}-\frac{2}{10}-\frac{3}{11}-..-\frac{92}{100}}{\frac{1}{45}+\frac{1}{50}+\frac{1}{55}+..+\frac{1}{500}}\)
a)Tính P,Q b) Tính tỉ số % của P và 3Q
So sánh A và B nếu :
\(A=-\frac{1}{2011}-\frac{3}{11^2}-\frac{5}{11^3}-\frac{7}{11^4}\)va \(B=\frac{1}{2022}-\frac{7}{11^2}-\frac{5}{11^3}-\frac{3}{11^4}\)
