Các câu hỏi tương tự
Chứng minh rằng:\(\frac{9}{10!}+\frac{9}{11!}+\frac{9}{12!}+...+\frac{9}{1000!}<\frac{1}{9!}\)
HÃY CHỨNG MINH :
\(\frac{9}{10!}+\frac{10}{11!}+\frac{11}{12!}+......+\frac{999}{1000}< \frac{1}{9!}\)
Chứng minh rằng \(\left(\frac{9}{11}-0,81\right)^{2008}=\left(\frac{9}{11}\right)^{2008}\times\frac{1}{10^{4016}}\)
Cho biểu thức A= \(\frac{2}{1}\times\frac{4}{3}\times\frac{6}{5}\times\frac{8}{7}\times\frac{10}{9}\times...\times\frac{100}{99}\)Chứng minh rằng 12<A<13
\(\frac{X-6}{7}+\frac{X-7}{8}+\frac{X-8}{9}=\frac{X-9}{10}+\frac{X-10}{11}+\frac{X-11}{12}\)
1.Tính
a)\(\frac{0,4+\frac{2}{9}-\frac{2}{11}}{1,6+\frac{8}{9}-\frac{8}{11}}\)
b)\(\frac{1}{99.97}-\frac{1}{97.95}-....-\frac{1}{5.3}-\frac{1}{3.1}\)
c)\(\frac{16^3.3^{10}+120.6^9}{4^6.3^{12}+6^{11}}\)
chứng minh rằng
E= \(\frac{9^{11}-9^{10}-9^9}{639}\) là số tự nhiênn
TIM X:\(\frac{x-6}{7}+\frac{x-7}{8}+\frac{x-8}{9}=\frac{x-9}{10}+\frac{x-10}{11}+\frac{x-11}{12}\)
\(\frac{1}{3}-\frac{3}{5}+\frac{5}{7}-\frac{7}{9}+\frac{9}{11}-\frac{11}{13}+\frac{13}{5}+\frac{11}{13}-\frac{9}{11}+\frac{7}{9}-\frac{5}{7}+\frac{3}{5}-\frac{1}{3}\) tính giup minh voi