Violympic toán 6
Các câu hỏi tương tự
Chứng Minh Rằng
a) \(\frac{1}{2}-\frac{1}{4}+\frac{1}{8}-\frac{1}{16}+\frac{1}{32}-\frac{1}{64}< \frac{1}{3}\)
b) \(\frac{1}{3}-\frac{2}{3^2}+\frac{3}{3^3}-\frac{4}{3^4}+.....+\frac{99}{3^{99}}-\frac{100}{3^{100}}< \frac{3}{16}\)
1.tính các biểu thức sau bằng một cách hợp lí
a.frac{108}{119}.frac{107}{211}+frac{108}{119}.frac{104}{211}
b.frac{15}{19}.frac{27}{33}+frac{15}{19}.frac{19}{33}-frac{15}{19}.frac{13}{33}
c.frac{-4}{5}.frac{13}{10}+frac{-4}{5}.frac{7}{10}-frac{-4}{5}
d.frac{frac{-2}{7}-frac{-2}{15}+frac{-2}{39}}{frac{5}{7}-frac{5}{15}+frac{5}{39}}
e.frac{3}{5}.frac{15}{7}-frac{15}{7}.frac{8}{5}
f.frac{2}{3}+frac{1}{3}.left(frac{-4}{9}+frac{5}{6}right):frac{7}{12}
h.frac{frac{3}{5}+frac{3}{7}-frac{3}{11}}{...
Đọc tiếp
1.tính các biểu thức sau bằng một cách hợp lí
a.\(\frac{108}{119}.\frac{107}{211}+\frac{108}{119}.\frac{104}{211}\)
b.\(\frac{15}{19}.\frac{27}{33}+\frac{15}{19}.\frac{19}{33}-\frac{15}{19}.\frac{13}{33}\)
c.\(\frac{-4}{5}.\frac{13}{10}+\frac{-4}{5}.\frac{7}{10}-\frac{-4}{5}\)
d.\(\frac{\frac{-2}{7}-\frac{-2}{15}+\frac{-2}{39}}{\frac{5}{7}-\frac{5}{15}+\frac{5}{39}}\)
e.\(\frac{3}{5}.\frac{15}{7}-\frac{15}{7}.\frac{8}{5}\)
f.\(\frac{2}{3}+\frac{1}{3}.\left(\frac{-4}{9}+\frac{5}{6}\right):\frac{7}{12}\)
h.\(\frac{\frac{3}{5}+\frac{3}{7}-\frac{3}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{11}}\)
g.\(\frac{3}{-4}+\frac{2}{7}+\frac{-1}{4}+\frac{5}{7}+\frac{21}{22}.\frac{66}{7}\)
k.\(\frac{27.18+27.103-120.27}{15.33+33.12}\)
l.\(\frac{\frac{2}{5}+\frac{2}{7}-\frac{2}{9}-\frac{2}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{9}-\frac{4}{11}}\)
Tính nhanh:
A=\(\frac{\frac{2}{13}+\frac{2}{15}-\frac{2}{11}}{\frac{68}{34}+\frac{68}{30}-\frac{68}{22}}+\frac{\frac{32}{10}+\frac{32}{14}-\frac{32}{18}}{\frac{17}{5}+\frac{17}{7}-\frac{17}{9}}\)
Chứng minh rằng: a)\(\frac{1}{2}-\frac{1}{4}+\frac{1}{8}-\frac{1}{16}+\frac{1}{32}-\frac{1}{64}< \frac{1}{3}\)
b)\(\frac{1}{3}-\frac{2}{3^2}+\frac{3}{3^3}-\frac{4}{3^4}+...+\frac{99}{3^{99}}-\frac{100}{3^{100}}< \frac{3}{16}\)
Nhanh lên nhé! Mk đang cần gấp.
left(20+9frac{1}{4}right):2frac{1}{4} left(6-2frac{4}{5}right).3frac{1}{8}-1frac{3}{5}:frac{1}{4}
frac{32}{15}:left(-1frac{1}{5}+1frac{1}{3}right) 0,2.frac{15}{36}-left(frac{2}{5}frac{2}{3}right):1frac{1}{5}
frac{-3}{7}.frac{5}{9}+frac{4}{9}.frac{-3}{7}+2frac{3}{7} 0,7.2frac{2}{3}.20.0,375.frac{5}{8}
Đọc tiếp
\(\left(20+9\frac{1}{4}\right):2\frac{1}{4}\) \(\left(6-2\frac{4}{5}\right).3\frac{1}{8}-1\frac{3}{5}:\frac{1}{4}\)
\(\frac{32}{15}:\left(-1\frac{1}{5}+1\frac{1}{3}\right)\) \(0,2.\frac{15}{36}-\left(\frac{2}{5}=\frac{2}{3}\right):1\frac{1}{5}\)
\(\frac{-3}{7}.\frac{5}{9}+\frac{4}{9}.\frac{-3}{7}+2\frac{3}{7}\) \(0,7.2\frac{2}{3}.20.0,375.\frac{5}{8}\)
\(\frac{1}{4}+\frac{1}{8}+\frac{1}{16}+\frac{1}{32}+\frac{1}{64}+\frac{1}{28}\)
Bài 1: Tính (hợp lý nếu có thể)
a) frac{8}{40}+frac{-4}{20}-frac{3}{5}
b) frac{-7}{12}+frac{-2}{12}-frac{-3}{36}
c) (frac{1}{6}+frac{-4}{13})-(frac{-17}{6}-frac{30}{13})
d) -frac{-5}{4}+frac{7}{4}-frac{-11}{7}+frac{2}{7}
e) -frac{1}{8}+frac{-7}{9}+frac{-7}{8}+frac{6}{7}+frac{2}{14}
f) frac{-2}{9}-frac{11}{-9}+frac{5}{7}-frac{-6}{-7}
Đọc tiếp
Bài 1: Tính (hợp lý nếu có thể)
a) \(\frac{8}{40}+\frac{-4}{20}-\frac{3}{5}\)
b) \(\frac{-7}{12}+\frac{-2}{12}-\frac{-3}{36}\)
c) \((\frac{1}{6}+\frac{-4}{13})-(\frac{-17}{6}-\frac{30}{13})\)
d) \(-\frac{-5}{4}+\frac{7}{4}-\frac{-11}{7}+\frac{2}{7}\)
e) \(-\frac{1}{8}+\frac{-7}{9}+\frac{-7}{8}+\frac{6}{7}+\frac{2}{14}\)
f) \(\frac{-2}{9}-\frac{11}{-9}+\frac{5}{7}-\frac{-6}{-7}\)
Tính hợp lí:
a, 75. ( -2frac{3}{25}+7frac{2}{75}-5frac{4}{15} )
b, 45.left(5frac{4}{15}-4frac{7}{9}-1frac{8}{45}right)
c, frac{-5}{8}+frac{14}{18}-frac{3}{8}+frac{2}{9}-frac{1}{2006}
d, frac{15}{29}-frac{8}{7}+frac{16}{14}+frac{14}{29}-frac{3}{8}
e, frac{1}{3.5}+frac{1}{5.7}+...+frac{1}{49.51}
Đọc tiếp
Tính hợp lí:
a, 75. ( \(-2\frac{3}{25}+7\frac{2}{75}-5\frac{4}{15}\) )
b, \(45.\left(5\frac{4}{15}-4\frac{7}{9}-1\frac{8}{45}\right)\)
c, \(\frac{-5}{8}+\frac{14}{18}-\frac{3}{8}+\frac{2}{9}-\frac{1}{2006}\)
d, \(\frac{15}{29}-\frac{8}{7}+\frac{16}{14}+\frac{14}{29}-\frac{3}{8}\)
e, \(\frac{1}{3.5}+\frac{1}{5.7}+...+\frac{1}{49.51}\)
cho A=40+\(\frac{8}{3}+\frac{7}{8^2}\frac{5}{8^3}\frac{32}{8^5}vàB=\frac{24}{8^2}+40+\frac{5}{8^2}+\frac{40}{8^2}\frac{5}{8^4}.\)