Các câu hỏi tương tự
Tính nhanh
1)A=\(\frac{7}{10.11}+\frac{7}{11.12}+\frac{7}{12.13}+...+\frac{7}{69.70}\)
2)B=\(\frac{1}{25.27}+\frac{1}{27.29}+\frac{1}{29.31}+...+\frac{1}{73.75}\)
3)C=\(\frac{4}{2.4}+\frac{4}{4.6}+\frac{4}{6.8}+...+\frac{4}{2008.2010}\)
Tính:
\(A=\frac{1}{25.27}+\frac{1}{27.29}+\frac{1}{29.31}+...+\frac{1}{73.75}\)
tính tổnga, Afrac{7}{10.11}+frac{7}{11.12}+frac{7}{12.13}+.......+frac{7}{69.70}b, Bfrac{1}{25.27}+frac{1}{27.29}+frac{1}{29.31}+.........+frac{1}{73.75}c, Cfrac{4}{2.4}+frac{4}{4.6}+frac{4}{6.8}+.............+frac{4}{2008.2010}
Đọc tiếp
tính tổng
a, A=\(\frac{7}{10.11}\)+\(\frac{7}{11.12}\)+\(\frac{7}{12.13}\)+.......+\(\frac{7}{69.70}\)
b, B=\(\frac{1}{25.27}\)+\(\frac{1}{27.29}\)+\(\frac{1}{29.31}\)+.........+\(\frac{1}{73.75}\)
c, C=\(\frac{4}{2.4}\)+\(\frac{4}{4.6}\)+\(\frac{4}{6.8}\)+.............+\(\frac{4}{2008.2010}\)
Tính
B= \(\frac{1}{25.27}\)+ \(\frac{1}{27.29}\)+ \(\frac{1}{29.31}\)+ ..... + \(\frac{1}{73.75}\)
tính các tổng sau
B= \(\frac{1}{25.27}\)+\(\frac{1}{27.29}\)+\(\frac{1}{29.31}\)+.................+\(\frac{1}{73.75}\)
Tìm số nguyên x
a) \(\frac{1}{3}+\frac{-2}{5}+\frac{1}{6}+\frac{-1}{5}\le x< \frac{-3}{4}+\frac{2}{7}+\frac{-1}{4}+\frac{3}{5}+\frac{5}{7}\)
b)\(\frac{5}{17}+\frac{-9}{4}+\frac{-26}{31}+\frac{12}{17}+\frac{-11}{31}< \frac{x}{9}\le\frac{-3}{7}+\frac{7}{15}+\frac{4}{-7}+\frac{8}{15}\)
câu 1:thực hiện phép tính (tính nhanh nếu có thể): a, frac{-7}{25}.frac{11}{13}+frac{-7}{25}.frac{2}{13}-frac{18}{25}b,frac{5}{7}.frac{1}{3}-frac{5}{7}.frac{1}{4}-frac{5}{7}.frac{1}{12}c,5frac{2}{5}.4frac{2}{7}+5frac{5}{7}.5frac{2}{5}d,75%-1frac{1}{2}+0,5:frac{5}{12}-left(frac{-1}{2}right)^2câu 2:tìm x biết:a, x+frac{1}{6}frac{-3}{8}b, frac{1}{2}x+frac{1}{8}xfrac{3}{4}c,2-left|frac{3}{4}-xright|frac{7}{12}d,left(2x-4,5right):frac{3}{4}-frac{1}{3}1GIÚP MIK VS MAI MIK PHẢI NỘP BÀI RỒI!
Đọc tiếp
câu 1:thực hiện phép tính (tính nhanh nếu có thể):
a, \(\frac{-7}{25}.\frac{11}{13}+\frac{-7}{25}.\frac{2}{13}-\frac{18}{25}\)
b,\(\frac{5}{7}.\frac{1}{3}-\frac{5}{7}.\frac{1}{4}-\frac{5}{7}.\frac{1}{12}\)
c,\(5\frac{2}{5}.4\frac{2}{7}+5\frac{5}{7}.5\frac{2}{5}\)
d,\(75\%-1\frac{1}{2}+0,5:\frac{5}{12}-\left(\frac{-1}{2}\right)^2\)
câu 2:tìm x biết:
a, \(x+\frac{1}{6}=\frac{-3}{8}\)
b, \(\frac{1}{2}x+\frac{1}{8}x=\frac{3}{4}\)
c,\(2-\left|\frac{3}{4}-x\right|=\frac{7}{12}\)
d,\(\left(2x-4,5\right):\frac{3}{4}-\frac{1}{3}=1\)
GIÚP MIK VS MAI MIK PHẢI NỘP BÀI RỒI!
\(E=\frac{1}{25.27}+\frac{1}{27.29}+...+\frac{1}{73.75}.\)
\(F=\frac{15}{90.94}+\frac{15}{94.98}+...+\frac{15}{146.150}\)
\(G=\frac{10}{56}+\frac{10}{140}+\frac{10}{260}+...+\frac{10}{1400}\)
Bài 2
\(\frac{1}{2^2}+\frac{1}{3^2}+...+\frac{1}{100^2}.\)
CMR A<\(\frac{3}{4}\)
Câu 1:Tìm x: \(\frac{x-1}{6}+\frac{x-2}{5}+\frac{x-3}{4}+\frac{x-4}{3}+\frac{x-5}{2}=5\)
Câu 2:Tính nhanh
a) \(\frac{1}{3.4}+\frac{1}{4.13}+\frac{1}{13.9}+\frac{1}{9.23}+\frac{1}{23.14}+\frac{1}{14.33}\)
b) \(\frac{4}{1.9}+\frac{7}{9.4}+\frac{9}{4.25}+\frac{7}{25.8}+\frac{11}{8.43}\)