Tính C:
C=\(\text{}\dfrac{1}{9.10}-\dfrac{1}{8.9}-\dfrac{1}{7.8}-....-\dfrac{1}{2.3}-\dfrac{1}{1.2}\)
Giúp mik với!!!
Thực hiện phép tính:
\(A=3.\dfrac{1}{1.2}-5.\dfrac{1}{2.3}+7.\dfrac{1}{3.4}-...+15.\dfrac{1}{7.8}-17.\dfrac{1}{8.9}\)
\(\dfrac{8^{14}}{4^4.64^5}\)
\(\dfrac{9^{10}.27^7}{81^7.3^{15}}\)
\(\left(\dfrac{3}{10}\right)^4.\left(0,3\right)^5.\left(\dfrac{10}{3}\right)^{10}\)
\(\dfrac{\left(4^3\right)^2.9^4}{6^7.8^2}\)
\(\dfrac{4^8.9^4}{6^6.8^3}\)
\(3^6.\left(\dfrac{1}{3}\right)^6.81^2.\dfrac{1}{27^2}\) TÍNH
Tính giá trị biểu thức
\(\dfrac{2^8-2^3}{2^5-1}\)
\(\dfrac{4^8.9^4}{6^6.8^3}\)
\(\dfrac{27^4.2^3-3^{10}.4^3}{6^4.9^3}\)
1/9.10-1/8.9-1/7.8-...-1/1.2 = ?
1+\(\dfrac{1}{2}\)(1+2)+\(\dfrac{1}{3}\left(1+2+3\right)\)+\(\dfrac{1}{4}\left(1+2+3+4\right)\)+...+\(\dfrac{1}{20}\left(1+2+3+...+20\right)\)
Tính:B=\(1+\dfrac{1}{2}\left(1+2\right)+\dfrac{1}{3}\left(1+2+3\right)+\dfrac{1}{4}\left(1+2+3+4\right)+...+\dfrac{1}{20}\left(1+2+3+...+20\right)\)
Tính B=1+\(\dfrac{1}{2}\left(1+2\right)+\dfrac{1}{3}\left(1+2+3\right)+...+\dfrac{1}{20}\left(1+2+3+...+20\right)\)
Tìm x, biết:
a) \(\dfrac{-1}{10}\) + \(\dfrac{2}{5}\)x + \(\dfrac{7}{20}\) = \(\dfrac{1}{10}\)
b) \(\dfrac{1}{3}\) + \(\dfrac{1}{2}\) : x= \(-\dfrac{1}{5}\)
c) \(-\dfrac{2}{3}\) : x + \(\dfrac{5}{8}\) = \(-\dfrac{7}{12}\)