Các câu hỏi tương tự
\(\frac{1}{5\cdot8}+\frac{1}{8\cdot11}+\frac{1}{11\cdot14}...+\frac{1}{605\cdot608}\)
tính
B = \(\frac{5}{2\cdot1}+\frac{4}{1\cdot11}+\frac{3}{11\cdot2}+\frac{1}{2\cdot15}+\frac{3}{15\cdot14}\)
Tính nhanh:
\(\dfrac{3}{2\cdot5}\)+\(\dfrac{3}{5\cdot8}\)+\(\dfrac{3}{8\cdot11}\)+\(\dfrac{3}{11\cdot14}\)
A=\(\frac{6,622 + 5,4×3,38 + 1,22×3,38}{33,1×7,1 + 33,1×12,9}\)
a, Rút gọn A
b,Tìm B biết 15% của B bằng A
D=\(\frac{6}{15\cdot18}+\frac{6}{18\cdot21}+\frac{6}{21\cdot24}+...+\frac{6}{87\cdot90}\)
E=\(\frac{3^2}{8\cdot11}+\frac{3^2}{11\cdot14}+\frac{3^2}{14\cdot17}+...+\frac{3^2}{197\cdot200}\)
tính giá trị biểu thức
a, 3^8 / 3^4 + 2^2 *2^3
b, 3* 4^2 -- 2 * 3^2
c, \(\frac{4^6\cdot3^4\cdot9^5}{6^{12}}\)
d, \(\frac{21^2\cdot14\cdot125}{35^36}\)
e,\(\frac{45^3\cdot20^4\cdot18^2}{180^5}\)
g, \(\frac{2^{13}+2^5}{2^{10}+2^2}\)
\(\frac{21^2\cdot14\cdot125}{35^3\cdot6}=?\)
Thực hiện phếp tính:
\(A=-\frac{7}{12}+\frac{11}{8}-\frac{5}{9}\)
\(B=5.\left(-2\right)^2-4.\left(-5\right)-20\)
\(C=\left(\frac{5}{7}.0,6-5:3\frac{1}{2}\right).\left(40\%-1,4\right).\left(-2\right)^2\)
Tìm x biết:
a) \(\frac{1}{5\cdot8}\) + \(\frac{1}{8\cdot11}\) + \(\frac{1}{11\cdot14}\) + .....+ \(\frac{1}{x\cdot\left(x+3\right)}\) = \(\frac{101}{1540}\)
b) \(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{x\cdot\left(x+1\right):2}=1\frac{1991}{1993}\)