Tính A=\(\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{18}+\frac{1}{19}+\frac{1}{20}}{\frac{19}{1}+\frac{18}{2}+\frac{17}{3}+...+\frac{3}{17}+\frac{2}{18}+\frac{1}{19}}\)
Hãy tính:\(\frac{\frac{1}{19}+\frac{2}{18}+\frac{3}{17}+...+\frac{18}{2}+\frac{19}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{19}+\frac{1}{20}}\)
tính \(\frac{\frac{1}{19}+\frac{2}{18}+\frac{3}{17}+...+\frac{18}{2}+\frac{19}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{19}+\frac{1}{20}}\)
\(\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{18}+\frac{1}{19}+\frac{1}{20}}{\frac{19}{1}+\frac{18}{2}+\frac{17}{3}+...+\frac{3}{17}+\frac{2}{18}+\frac{1}{19}}\)
Bài 1: Tính
\(\frac{\frac{1}{19}+\frac{2}{18}+\frac{3}{17}+....+\frac{18}{2}+\frac{19}{1}}{\frac{1}{2}+\frac{1}{3}+....+\frac{1}{19}+\frac{1}{20}}\)
tim D=\(\frac{\frac{1}{19}+\frac{2}{18}+\frac{3}{17}+.....+\frac{18}{2}+\frac{19}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+.....+\frac{1}{19}+\frac{1}{20}}\)
Tính
\(\frac{\frac{1}{19}+\frac{2}{18}+\frac{3}{17}+......+\frac{18}{2}+\frac{19}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}.....+\frac{1}{19}+\frac{1}{20}}\)
Các bạn giúp mình nhanh lên mình đang cần gấp
\(\frac{\frac{1}{19}+\frac{2}{18}+\frac{3}{17}+...+\frac{18}{2}+\frac{18}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+......+\frac{1}{19}}\)
đây là bài yêu cầu tính nhanh nha
1(\(\left(\frac{4}{286}-\frac{2}{7\times9}\right)\left(\frac{4}{286}-\frac{2}{9\times11}\right)......\left(\frac{4}{286}-\frac{2}{97\times99}\right)\)
2)\(A=\frac{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{19}+\frac{1}{20}}{\frac{19}{1}+\frac{18}{2}+\frac{17}{3}+...+\frac{2}{18}+\frac{1}{19}}\)