Các câu hỏi tương tự
tinh nhanh
A=\(\frac{3}{1}+\frac{3}{1+2}+\frac{3}{1+2+3}+\frac{3}{1+2+3+4}+....+\frac{3}{1+2+3+.....+100}\)
Tính: \(S=\frac{92-\frac{1}{9}-\frac{2}{10}-\frac{3}{11}-....-\frac{90}{98}-\frac{91}{99}-\frac{92}{100}}{\frac{1}{45}+\frac{1}{50}+\frac{1}{55}+....+\frac{1}{495}+\frac{1}{500}}\)
Giúp mình nha! ^_^
\(\frac{1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{99}+\frac{1}{100}}{\frac{1}{99}+\frac{2}{98}+\frac{3}{97}+...+\frac{99}{1}+100}=?\)
1) \(79\frac{19}{35}.\frac{7}{90}+15\frac{16}{35}.\frac{7}{90}\)
2)\(\left(3\frac{1}{5}-\frac{1}{11}\right).11\)
3)\(4\frac{1}{5}:\left(2\frac{1}{3}.1\frac{2}{5}\right)\)
4)\(13,2.\frac{15}{64}-\left(\frac{4}{5}+\frac{2}{3}\right):3\frac{2}{3}\)
tính nhanh
\(100-\left(1+\frac{1}{2}+\frac{1}{3}+.....+\frac{1}{100}\right)=\frac{1}{2}+\frac{2}{3}+\frac{3}{4}+...+\frac{99}{100}\)
Tính nhanh:\(\frac{\frac{1}{2}}{1+2}+\frac{\frac{1}{2}}{1+2+3}+\frac{\frac{1}{2}}{1+2+3+4}+...+\frac{\frac{1}{2}}{1+2+3+4+...+100}\)
\(\frac{\left(\frac{1}{2}+0,25+\frac{1}{4}\right)+\left(\frac{1}{8}+\frac{3}{2}+\frac{1}{8}+\frac{25}{100}\right)+\left(0,75+\frac{1}{2}+50\%+\frac{1}{4}+0,55+\frac{145}{100}\right)}{1x2x3}\)
Tinh:
\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+...+\frac{1}{90}\)
tinh
\(\frac{1}{1+2}+\frac{1}{1+2+3}+\frac{1}{1+2+3+4}+\frac{1}{1+2+3+4+5}\)