\(\frac{7}{2}+\frac{7}{6}+\frac{7}{12}+\frac{7}{20}+\frac{7}{30}+\frac{7}{42}+\frac{7}{56}+\frac{7}{72}+\frac{7}{90}\)\(\frac{7}{90}\)
=\(\frac{7}{2+6+12+20+30+42+56+72+90}\)
=\(\frac{63}{10}\)
=6.3
\(\frac{7}{2}+\frac{7}{6}+\frac{7}{12}+\frac{7}{20}+\frac{7}{30}+\frac{7}{42}+\frac{7}{56}+\frac{7}{72}+\frac{7}{90}\)\(\frac{7}{90}\)
=\(\frac{7}{2+6+12+20+30+42+56+72+90}\)
=\(\frac{63}{10}\)
=6.3
tính :\(\frac{3}{2}+\frac{7}{6}+\frac{13}{12}+\frac{21}{20}+\frac{31}{30}+\frac{43}{42}+\frac{57}{56}+\frac{73}{72}+\frac{91}{90}\)
\(\frac{7}{2}+\frac{7}{6}+\frac{7}{12}+\frac{7}{20}+\frac{7}{30}+\frac{7}{42}\)
\(\frac{3}{2}+\frac{7}{6}+\frac{13}{12}+\frac{21}{20}+\frac{31}{30}+\frac{43}{42}+\frac{57}{56}+\frac{73}{72}+\frac{91}{90}\)
ai lam di mk tick cho
chi tiết cách giải
B=\(\frac{5}{7}.\frac{14}{11}-\frac{5}{7}.\frac{5}{11}-\frac{5}{11}.\frac{2}{7}\)
C=\(1+\frac{2}{6}+\frac{2}{12}+\frac{2}{20}+\frac{2}{30}+\frac{2}{42}\)
D=\(\frac{0,75-0,6+\frac{3}{19}+\frac{3}{19}}{2,75-2,2+\frac{11}{19}+\frac{11}{91}}\)
\(\frac{3}{2}+\frac{7}{6}+\frac{13}{12}+\frac{21}{20}+...............+\frac{91}{90}+\frac{111}{110}\)
bài 1
\(\frac{18}{11}+\left(\frac{7}{4}-\frac{3}{5}\right):\frac{1}{2}\)
\(\frac{8}{5}-\frac{1}{2}:\frac{1}{4}\cdot\left(\frac{3}{7}+\frac{1}{4}\right)\)
\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}\)
Nối các phân số bằng nhau:
\(\frac{3}{8};\frac{14}{30};\frac{36}{42};\frac{7}{15};\frac{6}{7};\frac{9}{24}\)
\(\frac{3}{1x2}+\frac{3}{2x3}+\frac{3}{3x4}+\frac{3}{4x5}+\frac{3}{5x6}+....+\frac{3}{9x10}+\frac{77}{2x9}+\frac{77}{9x16}+\frac{77}{16x23}+...+\frac{77}{93x100}\)
\(\frac{4}{3x6}+\frac{4}{6x9}+\frac{4}{9x12}+\frac{4}{12x15}\) \(\frac{7}{1x5}+\frac{7}{5x9}+\frac{7}{9x13}+\frac{7}{13x17}+\frac{7}{17x21}\)
\(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}+\frac{1}{42}+...+\frac{1}{110}\) \(\frac{1}{10}+\frac{1}{40}+\frac{1}{88}+\frac{1}{154}+\frac{1}{138}+\frac{1}{340}\)
\(54\frac{1}{7}+\frac{1}{12}+54\frac{1}{7}\cdot\frac{5}{6}\cdot\frac{1}{12}\cdot54\frac{1}{7}\)