\(\frac{-9}{10}.\frac{5}{14}+\frac{1}{10}.\frac{-9}{2}+\frac{1}{7}.\frac{-9}{10}\)
\(=\frac{-9}{10}.\frac{5}{14}+\frac{-9}{10}.\frac{1}{2}+\frac{1}{7}.\frac{-9}{10}\)
\(=\frac{-9}{10}.\left(\frac{5}{14}+\frac{1}{2}+\frac{1}{7}\right)=\frac{-9}{10}.1=\frac{-9}{10}\)
Tính nhanh :
\(\frac{-9}{10}.\frac{5}{14}+\frac{1}{10}.\left(-\frac{9}{2}\right)+\frac{1}{7}.\left(-\frac{9}{10}\right)\)
Tính nhanh
\(\frac{-9}{10}\).\(\frac{5}{14}+\frac{1}{10}.\frac{-9}{2}\)+ \(\frac{1}{7}.\frac{-9}{2}\)
\(A=\left\{\frac{1999}{2011}-\frac{2011}{1999}\right\}-\left\{\frac{-12}{1999}-\frac{12}{2011}\right\}\)
\(B=\frac{2}{5}+\left(\frac{3}{11}+\frac{-2}{5}\right)\)
\(C=\frac{-5}{7}.\frac{4}{13}+\frac{-5}{7}.\frac{9}{13}+\frac{-2}{7}\)
\(D=\frac{-9}{10}.\frac{5}{14}+\frac{1}{10}.\left(\frac{-9}{2}\right)+\frac{1}{7}.\left(\frac{-9}{10}\right)\)
So sánh:
a)\(\frac{7^{15}}{1+7+7^2+...+7^{14}}\) và \(\frac{9^{15}}{1+9+9^2+...+9^{14}}\)
b) \(\frac{1+3+3^2+...+3^{10}}{1+3+3^2+...+3^9}\)và \(\frac{1+5+5^2+...+5^{10}}{1+5+5^2+...+5^9}\)
Tính nhanh:
M=\(\frac{-7}{9}.\frac{15}{49}.\frac{9}{7}.15.\frac{14}{15}\)
N=\(\frac{5}{9}.\frac{4}{7}.\frac{10}{3}+\frac{15}{45}.\frac{3}{7}.\frac{1}{2}\)
\(\frac{11^4.6-11^5}{11^4-11^5}:\frac{9^8.3-9^9}{9^8.5+9^8.7}\)
\(\frac{3}{5}:\left(\frac{-1}{5}-\frac{1}{6}\right)+\frac{3}{5}:\left(\frac{-1}{3}-1\frac{1}{15}\right)\)
\(\left(\frac{1}{2}-\frac{13}{14}\right):\frac{5}{7}-\left(-\frac{2}{21}+\frac{1}{7}\right):\frac{5}{7}\)
\(\frac{4^5.9^4-2.6^9}{2^{10}.3^8+6^8.20}\)
tính nhanh
a, \(\frac{7}{12}.\frac{6}{11}+\frac{7}{12}.\frac{5}{11}-2\frac{7}{12}\)
b,\(\frac{-5}{9}.\frac{-6}{13}+\frac{5}{-9}.\frac{-5}{13}-\frac{5}{9}\)
c,\(0,8.\frac{-15}{14}-\frac{4}{5}.\frac{13}{14}-1\frac{2}{5}\)
d, \(75\%.\frac{6}{7}+5\%.\frac{6}{7}+\frac{7}{10}.1\frac{1}{7}\)
tính nhanh
a, \(\frac{7}{12}.\frac{6}{11}+\frac{7}{12}.\frac{5}{11}-2\frac{7}{12}\)
b,\(\frac{-5}{9}.\frac{-6}{13}+\frac{5}{-9}.\frac{-5}{13}-\frac{5}{9}\)
c, \(0,8.\frac{-15}{14}-\frac{4}{5}.\frac{13}{14}-1\frac{2}{5}\)
d,\(75\%.\frac{6}{7}+5\%.\frac{6}{7}+\frac{7}{10}.1\frac{1}{7}\)
Tính nhanh nếu có thể......\(9\frac{2}{9}+\frac{2}{3}+7\frac{7}{9}\) \(\frac{5}{9}\times\frac{10}{11}+\frac{5}{9}\times\frac{14}{11}-\frac{5}{9}\times\frac{15}{11}\)
\(\frac{1}{6}\div\left(0,75+\frac{1}{6}\right)-50\%-\left(1\right)^2\)
