= 7.( \(\frac{1}{10}-\frac{1}{11}+\frac{1}{11}-\frac{1}{12}+\frac{1}{12}-....-\frac{1}{70}\))
= 7.( \(\frac{1}{10}-\frac{1}{70}\))
= 7.(\(\frac{7}{70}-\frac{1}{70}\))
= 7.\(\frac{6}{70}\)
= \(\frac{3}{5}\)
tính nhanh:
A=\(\frac{\frac{3}{7}-\frac{3}{17}+\frac{3}{37}}{\frac{5}{7}-\frac{5}{17}+\frac{5}{37}}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}-\frac{1}{5}}{\frac{7}{5}-\frac{7}{4}+\frac{7}{3}-\frac{7}{2}}\)
giải chi tiết nhé các bạn
Rút gọn:
a) \(\frac{10.11+50.55+70.77}{11.12+55.60+77.84}\)
b) \(\frac{1.3.5.7.....49}{26.27.28.29.....50}\)
Tính giá trị biểu thức sau:
A = \(\left(\frac{1}{7}+\frac{1}{23}-\frac{1}{1009}\right):\left(\frac{1}{23}+\frac{1}{7}-\frac{1}{1009}+\frac{1}{7}\cdot\frac{1}{23}\cdot\frac{1}{1009}\cdot\right)+1:\left(30.1009-160\right)\)
tính nhanh A=\(\frac{7}{8}:\left(\frac{2}{9}-\frac{1}{18}\right)+\frac{7}{18}:\left(\frac{1}{6}-\frac{5}{12}\right)\)
Tính
\(\frac{-3}{5}.\frac{2}{7}+\frac{-3}{5}.\frac{5}{7}+2\frac{3}{5}\)
Tính nhanh:
a)\(\frac{24\cdot47-23}{24+47-23}\cdot\frac{3+\frac{3}{7}-\frac{3}{11}+\frac{3}{1001}-\frac{3}{13}}{\frac{9}{1001}-\frac{9}{13}+\frac{9}{7}-\frac{9}{11}+9}\)
b)\(\frac{1+2+2^2+...+2^{2012}}{2^{2014}-2}\)
\(\frac{-5}{7}.\frac{2}{11}+\frac{-5}{7}.\frac{9}{11}+1\frac{5}{7}\)
\(M=\frac{\frac{3}{5}+\frac{3}{7}-\frac{3}{11}}{\frac{4}{5}+\frac{4}{7}-\frac{4}{11}}\)
\(B=\frac{1}{2}\)+\(\frac{-1}{5}\)+\(\frac{-5}{7}\)+\(\frac{1}{6}\)+\(\frac{-3}{35}\)+\(\frac{1}{3}\)+\(\frac{1}{41}\)
E=40+\(\frac{3}{8^{ }}\)+\(\frac{7}{8^2}\)+\(\frac{5}{8^3}\)+\(\frac{32}{8^5}\)
F=\(\frac{147}{7^3}\)+4+\(\frac{35}{7^7}\)+\(\frac{4}{7^2}\)+\(\frac{27}{7^5}\)+\(\frac{-9}{7}\)
đây là toán lớp 6 lên các bạn đừng thắc mắc
